It depends on what your photo needs are.

Robin is correct that the K20D is still a very fine camera, and produces excellent images. Even my Canon Pro (1D) user friends are impressed in what it can do. However, there are a lot of circumstances where the K-5 far exceeds the K20D (not in IQ at low ISO, the difference is small) but other areas such as low light (I use a lot due to official Theatre tog where light is an issue) more accurate AF - the AF on the K20D is beginning to be a problem for me at fast apertures - probably due to the number of shots I have taken with it - 30000+.
The Dynamic range is better, less likely to be fooled by major changes in light and dark, such as a person in a black suit and white shirt.
FPS- not given it a work out on this yet, but looks good.
Mirror slap on the K20D is a concern, the K-5 is a lot better in this respect, no kickback you feel in the hand.

For studio work and Landscapes, there is little difference between the K-5 and K20D, but you are working at Low ISO and smaller apertures, and you are slowed down. but for all other aspects, the K-5 is far better.

I was in the lucky position to afford and purchase the K-5, which in one fell swoop iradicate the problems I was having with the K20D, to which for the work I was doing, became unreliable. If I bought the K-7 instead, I might not be so enthusiastic.

I agree with the 35mm F2.4

The lens is a bargain! It only has a plastic bayonet, but don't let that put you off. The lens is light and fits snugly on the body (whether K20D, *istDS, K-5 etc) In fact using it on the K-5 which demands high quality optics, it is great.

I can't recommend it enough.

£199 at Park? Bargain!

A great lens, but a tad flimsy.

During new year, I had mine on the end of the K20D and in a padded bag.
The bag dropped from less than one metre and everything seemed okay. However a small area of the filter screw on the lens has snapped off
I can still put filters on, and the optics are fine, but not happy.....

Anyway, I digress, have you tried Cameraworld? or Mathers of Lancashire?
Both might have one in to buy.

In some ways it is a shame that they have appeared to stop making it, but not surprised. It was probably the first "pro" spec DA zoom that came out (you could order it with the *istD way back when) and is possibly lacking in resultion (but on the K20D it was fine)
With the 17-70 appearing, was probably the death knell for the 16-45.....

Still, if you can find one, grab it while you can

Yes I should have clarified that. the voltage is still the same, just how long they last in use.
Still, the 7daysop own ones should have lasted longer than old jessops ones when it came to the number of times they have gone through the cycle (charge-use-charge-use etc)

Tiger

Start saving. The K-5 is my fave body, and then some!

I can't believe how much better it is over my K20D, words cannot describe......

Seriously, get a K-5, all those shortcomings with earlier bodies have gone.

Hi Pete and welcome.

In all honesty, any DSLR will be far superior to a bridge camera when it comes to birds. You have a far larger sensor and better optics.

When it comes to specifics, the K-r will be a fine camera to get birds, and the 55-300 will be okay (not from an IQ point of view - which will be excellent, but from its reach)

I have shot birds with a 300mm lens, but the reach was too short. Something that will go to 500mm will be better. Even my old Sigma 170-500 is good when it comes to birding.

Now, your second query. Canon or Pentax.

Well the reality comes down to price.
The K-r is getting a great reputation as a mid range DSLR (and has features that Canon can only dream of - this is not Canon bashing, far from it). Bodies are much of a muchness in the same price band, with some exceptions.

It comes down to lenses and price.

Now, if you really want to get a 500mm lens with Pentax, you get a reasonable price Sigma and will get excellent results.

However, if you go down the Canon route, you can either, have the same Sigma Lenses, or Canon's own 500mm lens, which, I am not kidding, is big, heavy and priced the same as a small car.
I have a few friends who are Canon users, and they have 500mm Lenses with Pro spec DSLR's. Yes the images are great, but in the cold light of day, are their EOS 1D mk4 and 500mm F4 ten times better than my K20D and Sigma 170-500 combo? Of course not! It is the law of diminishing returns.
So unless you are a Pro photographer or someone who is very flush with cash, stick to a K-r and a Sigma 150-500 (or second hand 170-500) and enjoy taking photos of birds. You will get results that you are proud of

Hope this helps

I have used various AA rechargables for both cameras and flash guns and I can confirm the following:-

Enloops are the best for holding the charge for weeks on end. But have less power (not that is too much of a problem)

If you are a frequent user of the camera, then Uniross are great!

Jessops own are not bad at all, I have a set of 2000mh even some 1300mh which still work

7dayshop own brand are rubbish but cheap! initally their 2500 and 2700 were great to start with but after 2 years are useless, will not charge at all.

Hope this helps.

Oh don't worry Oggy, I am going from what others and reviews has said.

However as an owner of the 170-500mm I know how sharp it is at 500mm and F8 - Sharp.....

Under £1000? plenty of options.

But personally I would go down the 150-500 route. Even if the lens is a bit soft after 450MM, you still have upto 450mm to play with.

Thats my tuppence worth