It will have to be a handloader as you would struggle finding factory loaded ammo.
If you base your rifle on a short action length then when trying to load the 260 with heavier bullets you have to compromise powder capacity by seating the bullets deeply, other wise then will not fit in the short action length magazine. So they work best with lighter 6.5mm bullets.
Other alternatives are the:-
6.5X55 long action rifle, versatile, and you can get factory ammo but the velocities are a bit modest.
6.5X284 flat shooting would work well with heavier bullets but burns out barrels after about 1,500 rounds.
6.5-06 like the 284 flat shooting and a good choice for heavy bullets say, 130+.
6.5X47 getting rave revues for it accuracy, it is based on a 308 action length, works best with lighter bullet weights.
Personally I would just get 6.5 caliber rifle on your ticket (if your FLO will let you) then decide what you want to do with the rifle and make you choice from there.
It is short throated, and tight necked and I only use 100 Gn bullet tips, but it knocks everything down very effectively up to and including Fallow Bucks. I only exclude Red Stags, as I have not personally shot one with the rifle.
Recoil is very gentle with light bullets, it is a delight to shoot.
I echo the comments about factory ammunition being difficult to find, , however I have always rolled my own , so it is not an issue for me.