Old thread, but many of the suggested rifles are still out there. I can think of a bunch of very good new or used heavy-barreled varmint rifles chambered in .22-250 out there, e.g.: Tikka and Sako Varmints, Ruger Mk. II Varmint, Remington 700 VS, VLS, VSSF, or a nice used 40-X (and the new 783 laminated Varmint which is getting good reviews); CZ 550 Varmint (how come none of these or a 557 replacement version now available?), Browning, Savage....you get the picture. I can vouch for the Remington, Ruger and Savage, as I have/have had each.
Only problem is, I've fallen hard for the .22 cal 53 grain Hornady V-Max, and the standard barrel twist rate for the .22-250 for almost all manufacturers is 1:14"; that longer, higher-bc bullet needs at least a 1:12 for stabilization (not gonna get into the 1:9 and faster here, of which a few brands are now offered in; those don't interest me anyway as I'll just pull out a 6mm if I need more horsepower or wind-fighting ability). Savage is the only off-the-rack rifle in '250 that comes in a 1:12 twist. I bought a $300 Cabela's FV special and it shoots those 53 V-Maxes into 1/2 inch easily — and some factory 55-grainers, too.
If money is no object, Coopers are hard to beat; I have three in other chamberings. My "dream" .22-250 would be a Cooper Model 54 repeater (the 1:12 twist is standard), but it might be tempting to "upgrade" to an AI, or maybe go to a Swift for a change.