I just updated my 6.5 Grendel web page. I load a lot of 123 Amax and 123 Scenar. If you would like a different bullet, let me know and I can load those for you. I've done some 130 Berger AR hybrids, 129 SST, 129 LR AB, and several others, also.
I use ammoseek. Bought from many of the websites on there with no issues, SGAmmo, outdoor unlimited, red river, etc. That being said, I have bought from Chad at dallas reloads as well and was happy with the ammo I got. If you are going for cheapest factory ammo, browse ammoseek and make sure to factor shipping.