As far as true varmint rounds I would go with the 223 or 22-250 for a starter, the 22-250 would probably be a better choice if you will be limited to only one, you can do more with the 22-250, plus if you dont reload both the 223 and 22-250 can be had in a wide variety of factory loads, some of them are really good loadings, as far as guns it would depend on how much money you wish to spend, you can get a new Savage for around $350, I dont personally have a Savage but I hear they are top notch, or you can go up to the next tier of rifles and get a Remington or Ruger for around $550 roughly for a Varminter, I have a 700VS in 223 with a 6X18 Leupold and a 700VLS in 22-250 with a 12X Leupold and I love them both, I use the 223 for the most part because most of my shots are within about 250 yards and the 223 is a joy to shoot, I would tend to agree with the gentleman before and say look at as many different varities as you can before you make your choice. Good Luck