Jake
The only down side to faster twist rates is it seems to magnify bullet and load imperfections, so you'll need to work a little longerfinding a good factory loading or working on a reload.I would opt for the 12FV though in 22-250, it's closer to optimum with a 1 in 12 twist. If your fixed on the 223 round take a look at the newRemington 700 SPS Varmint which does have a 1 in 12 twist and should be less finicky, price should be close.

Head
The RRA Varminter only comes in 1 in 8, I had this very gun with the 16 inch barreland it shot .5 groupswith Lake City55 GrainFMJ, so I think the lighter bullets are not a problem in the long run,but faster twist rate does magnify bullet imperfection's though, so use a quality ammo like Black Hills or reload with quality bulletsand powders withlow deviations.