It would be Squirrels and Rat, so the more compact the better, someone suggested a Edgun Lelya.
Leyla is supposed to be good - never played with one ( I think there's an upgraded carriage for them or it may be the Matador) - if it's built like the Leshiy's it will be pretty bombproof.
from what I own or have used/owned
Compact and cheaper as has been mentioned - P15 (dovetail rail), mine's used with a Pard008S and is my usual vermin gun, P35 - it's a P15 with forward cocking and Weaver rail both very light, Kral NP-02 - not so compact with the required moderator but has combi rail - not as light as it looks, Kral Empire XS - extremely compact - they also do an X with bottle and longer barrel but still compact.
Compact and more expensive -
Brocock Ghost, played with the other week - prefer my Daystate Renegade
Daystate Pulsar
Airmaks Krait - couple of mags through and was good
Cricket
Vixen
If you want to do your budget - Rapid or MFR - Rapid is bombproof if it hasn't been butchered, MFR is, in my mind, is still just about the best allrounder, light, damn near perfect balance, quiet even with the standard shroud and not overly long.
My choice if you're worried about it getting knocked about a bit but not worried about giving them a bit of a fettle- P15/35 or one of the rebranded versions or a Kral - will do all you need and more and leave you a big chunk out of your budget for a thermal spotter
