I have a BDL in 30-06 caliber... Fine rifle, but for the relatively same cost, I purchased a Browning A-Bolt in the 7MM Rem. Mag. WOW, what a difference... I love my 700, but the Browning has a 60 degree throw on the bolt, so you don't bang your hand against the scope every time you rack one in.
If you do decide on a 700, my suggestion is to get one that is designated as a DM (Detachable Magazine). Some 700's, like mine, have a spring that holds the mag in place, but when it is released, the bullets go everywhere... So, the DM was brought about (which was a design taken from the stock Browning A-Bolt).
As far as the caliber you go, EVERYBODY has an opinion... If you are hunting over open field, a flat trajectory bullet like .308 is outstanding (when my dad was a sniper for our local sheriff's dept., he used a 700 BDL with a necked-down .308 because it was so flat shooting, plus it had good penetration). The problem with the .308 is that if you hunt in cover, the slightest nick of a bush, cattail, etc. will knock the bullet off line.
If you will be hunting in timber, brush, etc., the 7MM Rem. Mag (outfitted with a BOSS so as not the blow you against the tree) would be a good idea. I've personally shot up to 400 yds. in Kansas with the 7 Mag, and it has always been good to me.
If you go to Winchester's website, you can view the ballistics on all calibers and see what their muzzle velocity, drop compensation, etc is. That will help you decide on the caliber that is right for you. A .308 or 7 Mag or .270 would most likely be the most beneficial... Good luck.
Just my $.02, although it's more like a dollar LOL
http://www.browning.com/products/catalog/firearms/detail.asp?value=001B&cat_id=035&type_id=008http://www.browning.com/products/catalog/firearms/detail.asp?value=001B&cat_id=035&type_id=002