From your posts I can only assume that the current financial restraints & severely limited budgets do not apply where you are. There's absolutely zero chance of any school (at least in my local area) even considering the services of a professional consultant, the money just ain't there. My kids primary school has a small vocal PA with 2 mics, as there's only 2 mics they only have 2 mic cables (no spare) so if 1 mic cable fails they either get someone to repair it or make do with 1 mic, it really is that tight. Recently I was asked to offer advice on a replacement PA and after sourcing some pretty basic systems for them told them it cost in the region of £800 - £1000, after which I was stared at in horror & dumbfoundment amid cries of 'seriously' & 'really'..! Things are the way they are, corners HAVE to be cut at every turn unfortunately.
Mac G5 Dual 2.3/6gb Ram, MOTU 828mkII, Yamaha 02r, DBX 286A, Logic 8, Roland SRV-3030D, Roland JV-1080, Roland JV-1010, Emu Proteus 2000, Roland SC55 MK2, Tascam DA-30 MK2