In order to get the low notes 5 strings have as cheaply as poss, I was thinking of stringing a 4er BEAD. Are there any tensioning issues? It would done on an acoustic, so it would have a wooden bridge. Presumably the only other thing to worry about would be filing the slots in the nut to make room for fatter strings. Note too that I'm not bothered about the acoustic sound, but am bothered about the amplified sound. I fear I'm being daft, but 5 string ABGs are thin on the ground in the UK, and those that are available look dull.