FX Impact 22/25 or Royal 500 which would you buy??

I'm at a delima. Currently I have a Bobcat FAC in 22 caliber and enjoy punching paper and shooting starlings and grackles, but like many air gunners I find I want something with a little more punch. I've been thinking about the Impact in 25 caliber along with the extra 22 caliber barrel. I really like the "look" of the gun and being able to change calibers has it's appeal!!. But then there's the 500 in 25 caliber only. Love the idea of 25 caliber and good accuracy at 45 meters and being able to stretch out the range. I know it's too early to get any reviews of the Impact. But I'm hoping for the Impact to be as accurate or more than the 22 Bobcat. Not in a rush to purchase either yet as the Impact is still months away.

..and what about attaching a bipod to the Royal?? Does it need a bottle band or is it possible to attach a rail to the stock??

Currently my effective range is 45 meters and not much beyond.

A side question...Will ballistics for the 25 Royal and 22 Bobcat be about he same within 45 meters???

I welcome any comments.
 
Tough to answer your questions with the Impacts not being out yet. 
I think the biggest differences in your two picks would be the weight and length. The Impact seems like it's going to be an excellent hunting platform in that it should be light weight, breaks down, and is a bullpup. On the other hand, the 500 might be better suited for more of the benchrest type of shooting in that it is much longer, heavier, and a full length rifle. I think the question you have to ask yourself is what will you be using it primarily for? Would you rather (possibly) sacrifice hunting ability or target shooting ability? 
I owned a 500 for a short while and I think your best bet would be to get a barrel band. You'd be putting a lot of stress on that little piece of wood/plastic under the bottle. But, I've seen it done both ways successfully. 
I think both choices will be terrific at 45m. It may come down to you and your preference of weapon. Some shooters don't do well with the bullpup platform while others can perform equally with either style. 
I definitely think you are going to get the added punch you're looking for by moving up to .25 cal! I was really impressed at the difference it made for me both in knockdown power and stability in the wind. 
I hope this helps, good luck with your choice! 
 
Thanks Tominco, why did you get rid of the 500..just curious..

yeah the length of the 500 has me a little concerned. and the weight of the Bobcat I wish was less. I DO prefer a hunting platform.....My main pleasure is hunting grackles in the back yard. I have no problem with the bullpup design and do like the thought of the versatility of the Impact. Kind of assume the smaller gun would get more use as it's just more handy to pick up. I've got plenty of time to mull over the two. I just hope the accuracy of the Impact is as good as the Bobcat and at this point it's anybody's guess.