DC power supplies

    I'm currently building a power supply for a tesla coil or magnifier-- the
power level will be somewhere around 5kva.  I will be doubling an 8kv power
supply to 16 kv DC, using a capacitor and diode assembly.  How would
utilizing a
DC supply differ from using AC?  I'm hoping that it will have more advantages
than disadvantages-- particularly in the capacitor area, since it seems
customary to halve regular capacitor ratings when AC is concerned.  However, it
may just be that this is due to the RF curcuit and not the power supply itself.
            Comments welcome.