I have not read every response. Here is my take to the OP.
Go heavy for caliber bullets. This means a fast twist barrel. 1:7" to 1:7.75" would be my suggestion depending on velocity expected. Run a 133 Elite, 134 ELD-M, or 135 Hyb. There are a few others like the Chinchagas as well. But I have no experience with them.
What are the expectations for desired yardage you want to be able to shoot?
What is the intended purpose? Hunting, I assume. Deer-sized game and down? Do you plan to hunt anything much bigger? Like black bear, elk, etc.? If you plan on shooting 1000+ rounds in a couple years, that will help determine what would be a good fit too.
Do you need head stamped brass? Like if you go to Mexico, Canada, Africa? If so, that limits what you can go with.
.25-06 Rem, 25SST, 25CM, .250 Savage, .257 Roberts, .257 Wby.
If not, that opens up more viable options.
25PRC, 25 PRC/SI, .250AI, 25 Souper, 25 SLR, 25 MBK, 257 Roberts AI, 25SS, 25 Max, 25 SAUM, 25-.284 Win, .25-06AI, 25STW, 25 RUM, etc.