I built a coil gun, and charged the caps with a simple voltage doubler straight from the mains (but with 700v caps). Its dangerous this way, but coil guns are fairly out there anyway, so you take risks ;-).
The charge time is not important, so a simple circuit will do, you cant charge straight from the mains via a bridge, the surge current with cause havoc.
Are you then seriesing them up for the money shot, or in parrellell?.
Triggering these mothers into the coil is no walk in the park, a relay is not really the go, the contact arcing is horrendous. A monster 1200V 1Kamp SCR is the go, worked a treat, fast and clean. I inserted a bolt into my coil, and it shot clean across the workshop and destroyed a shelf ( well, dented it).