First, go make about a dozen copies of your C&R. Send to at least AIM Surplus, J&G Sales, Southern Ohio Gun, Century, Brownells, and Midway.
Now, best deals depend greatly on what you are interested in.
In rifles, the Moisin-Nagant is the big game in town. Decent rifles, loads of surplus ammo, and dirt cheap.
In pistols, the big deals are the Cz-82s. Tokarevs, too. And the Walther P1s just got classified as C&R, be sure to snap one up.