There's a lot of good 25 caliber bullets available that would meet your requirements. Either the 100 or 120 grain partitions, the 100-120 grain Speer, Hornady or Sierra offerings, even the good old Hornady 117 round nose would serve you well in the role you describe.
If I was only ever going to hunt deer the rest of my life and could have only one rifle with which to hunt them, I'd chose the 257 Roberts and a 100-120 grain bullet. I'd just chose the one my rifle shot the best.
