The TSX has shot great out of all my guns,1" or less. a few friends say they haven't grouped well for them but that's always the case. I've taken deer, elk and moose with them and had perfect results.
264,
A Rifles Inc gun would be a fantastic choice, Lex does a Great job. I have a LW 70 built by him in 300 win mag and I'm shooting 180 TSX bullets at 3240 fps giving 3/4" groups. It's clear to see you're a 264 fan and so am I, but if you're going to have Lex build you a rifle and you want something like a 264 only a little better give a 270 WBY some thought. he'ld build it with no free bore, it really is a better round when done this way no kidding. a little more bullet weight, a little faster and a MUCH better bullet selection. just something to think about.