Well, there is no exact answer for making high power lyden jars but, remember the bigger the surface area the bigger the pF rating. Personally I would use 10x 1 gallon glass lyden jars for 5 on each terminal parelleled for high currents. Optimum glass diaelectric is thin, pyrex glass with lots of surface area 10"x5" is good. USE aluminized foil tape to get the best results, make sure you smooth down all the edges of the foil so you don't loose capacitance from corona discharges. An alternative to this lydenjar cap is to build a massive DC plate cap out of glass/ or PE plastic wich could hold 100-450Kvdc. You could easily exceed 100-200nF if you placed the plates under mineral oil. NOTE: 100nF cap is dangerous and can hold a lethal charge. DISCHARGE THE CAP WITH INSULATED TONGS! If you are just looking for a slight increase in spark strength, 1 or 2 jars will do nicely on each terminal.