Do you want a semi auto, bolt action or drop/lever/falling block rifle?
You may have seen an ad for either Cooper Arms of Montana or Dakota Arms for their varmint series of bolt action guns...
Semi auto = AR15 clones by a number of makers, Insight, Tromix, SSK Ind. etc.,
Falling block = Copies of the Winchester Hi/Lo wall 1885 rifle abound from Browning, Ballard etc., Dakota 'Lil Sharps rifle, Ruger Nmbr. 1V,
Drop action = T/C (Thompson Center) Encore or Contender or E Arthur Brown Model 97 or SSK Ind.,
Bolt Action = Cooper, Kimber, Remington, Ruger, Browning, Savage, Weatherby, Dakota,
Do you want a varmint weight and configuration--heavier barrel, straighter stock or a field/carry sporter?
What will be your intended game and most importantly at what range? If you're talking within 150 yds then a .17 HMR rimfire round will handle most vermin, varmints and fur bearers for a lot less money...If you're talking beyond 600 yds, you'd better be looking at a larger diameter calibre shooting heavier bullets...the .204 is a great 200 to 500 yard cartridge and if used on small game within those ranges, it is deadly...This is not a deer/pronghorn cartridge besides the fact that it would be illegal to use it for them...
Have fun, it's a great cartridge, very flat shooting, quite quiet and I've yet to see one exit the side of a coyote at 100+ yds...