If your going custom you need to be looking at the 308warbird. None of the previous rounds mentioned can come close to it. Second you want to take weight into account Carbon fiber. If your going with the 700 action you need to get rid of the 700 claw and replace it with the sako extractor, now you have an action to talk about. Now the trigger should be a jewel nothing tops it, crisp 2.5-3 lbs. zero creep just POW. Muzzle break by vias and now you've got a custom rifle that will weigh with a 26 in brl. around 5.6-6.0 pounds and hammer any north american game out to 700-800 yrds with any thought. just my 2 cents
1/2 inch groups all day

Here is mine
http://i157.photobucket.com/albums/t52/hwcolganiii/IMG_0920-1.jpg
http://i157.photobucket.com/albums/t52/hwcolganiii/IMG_0923.jpg
http://i157.photobucket.com/albums/t52/hwcolganiii/IMG_0925.jpg