Low-Carb Grow! is a good, all round protien, probably the best bang for yer buck (even with the very expensive M. Casien in it). It also tastes good. Really. No Joke.
You can also buy pro at wholesalers and stuff if you want to buy at 20+ lbs at a time, but keep in mind many times, although the quality is good, it tastes like hot trash dumpster juice...and now you got 20+ lbs to chug down. Enjoy!
There are many companies who make a good WPI or WPI/C blends out there (although I'm reluctant to name them on my fav. site). But as far as a WPI/M.Cas blend (a damn near 50/50, I might add, and it tastes GOOD --if you've ever tried M.Cas by itself) Biotest does it the best.
-endorsement whoring since birth