where is the best place to have a stock blank turned into a 2 pcs rifle stock

There are several places. One I have used for both two piece and one piece is Show-Me Gunstocks. Very reasonable prices and fast turn around. Donnie Gemes can be reached at:
Show-Me Gunstocks
19557 Quail Ridge Rd
Warsaw, MO 65355
(660) 438-4568

These are not "drop-in" stocks. The do require final inletting, shaping and finishing.

There are a number of members of the ACGG that do this. Go to the site and about half way down you will be able to download the "directory of custom gunmaking services"

http://acgg.com/

I highly recommend both Show-Me and Treebone Carving. www.treebonecarving.com/