Bought mine at DelCity.net.

http://www.delcity.net/store/Open-Barrel-Terminal-Ratchet-Crimp-Tool/p_714008

In spite of description, it does go to 10 GA wire. This is the one that my mechanic ended up buying too. It also has an adjustment screw on it for tweaking the crimp.

I also bought http://www.delcity.net/store/Double-Insulated-Terminal-Crimp-Tool/p_665741 for insulated terminals. I used the heat seal insulated terminals when needed, but if you crimp that type of terminal, you use the crimper for one size larger wire to accommodate the thick insulation.