I have a number of semi-customs built on Ruger MkII's and one on a Tang Safety. If you like the ruger action and you can meet your weight requirements with a ruger, they work fine. All mine are sporting rifles but they shoot as well as similar rifles built on Remington actions.
Two things I would Like changed, or rather have available in the aftermarket, would be a the McMillan MKII classic made in EDGE and someone to make rings that weigh about half what The stock Ruger's do.
Frankly if your making a LW rig the ruger isn't the place to start, but I have found that a 22" ish #2 contour and the MCmillan MKII classic make a reasonable rifle that both carries well and shoots well.
I just picked up a MKII in 7mm SAUM..not sure what to make it into yet. 338WSM?