Re: PacNor #5 or #6 pictures?
Unless you intend to pay for fluting, consider the weight and your stock's barrel channel clearance.
The light varmint is a fine contour. The Palma and #7 and heavier contour barrels are primarily for balance and to dampen recoil, plus to give some heat absorption for rapid fire competitive stages. Firing from bags or bipod, the benefits of lesser movement under recoil a heavy barrel gives are also a plus.
Heavy barrels look cool, until you start hiking with them. An 18# rifle is practically a crew-served weapon, or ought to be. 14# is about the upper limit of comfort unless you are training for triathalon stuff.
Lighter is going to be more versatile. With Pac-Nor, you won't be giving up any accuracy by choosing a #5 or light palma over a heavy, unless you're intending to do longrange benchrest. If you're gonna carry your rifle to the firing line in a cart, go as heavy as you can. If you think you may ever carry the piece afield, make every ounce count and leave about 3-4lbs for your scope and mount system.
All the "good stuff" weighs like hell.
A balance is important...