I have a FoxPro FX3 - it has more than enough volume for me, and 32 sounds selection are fine for my sets. FoxPro has a new model, the Scorpion, that is smaller than the FX3 and gets good marks from new owners. FoxPro's are not inexpensive, but they are well made. The "best" unit is a personal decision - cost, size, model, manufacturer, etc.
The Byron South DVDs are very well done - he does a good job of explaining his tactics, etc., not just showing his kills (which are included)and pushing his sponsor's advertising.
I bought mine from
www.allpredatorcalls.com and found them to be a great, family-owned company that has first-class service: They have a toll-free number you can use to get good info.
Callers work well, in conjunction with good tactics.
Check out
www.predatormastersforums.com/ for more info.