I'm starting to get together a bunch of ideas for the electronics for my next bass (fretted 6), and one thing I really would like to do is be able to run the active electronics from a phantom-powered, balanced XLR cable. The hardware isn't really a big deal, I've got the necessary connections as far as building is concerned. One thing I do need to know, however, is what wattage of power supply I am going to need, and any other specifics that it should have in order to run an 18 (or maybe 27) volt system comprised of one (1) very unique 5-band preamp and pickup select/blend system, three (3) EMG active pickups (bridge to neck: 45J-45TW-45DC), and one (one) piezo bridge system, all capable of running off internal rechargeable batteries or the external power supply, and outputting to XLR, 1/4 (for when you've got to run on battery), and 13-pin MIDI (so I can get individual signals for each string, and then really go wild). Complicated and almost certainly unnecessary, I know, but I really really want it, and would like to do as much of it myself as possible. So, to recap: what wattage of power supply should I look for in order to power all that stuff up there at 18 to 27v? What other special characteristics (if any) should I look for? Thanks!