Would Appreciate Some Advice

[GKing]

I'm an "old" retired guy. Want to buy a pellet gun, primarily for target and plinking, but also for small pests around the farm and an occasional squirrel.

I have decided to get a pretty good gun - something in the 1000 fps range. Considering Beeman R9, RW77, and RWS 48.

Here are my questions:

1) Advantages / disadvantages of barrel cocking vs lever cocking?

2) Accuracy any different between barrel and lever cocking guns?

3) Any other considerations favoring barrel vs lever cocking?

4) 177, 20 or 22 caliber - pros & cons

5) preference between Beeman and RWS? - I'm primarily interested in accuracy and of course quality of construction.

Thanks in advance for your advice

George