Also, behringer mixers, compressers and EQ's do the job Their amps and speakers aren't bad either, just make sure
you fill in the warranty things and send them away! By the way they have never let me down, they make millions of these things so obviously, some will go wrong, just run what you get hard for 5-10 mins and if it can't handle it get it replaced.
If you are doing a band with a drumkit with aims of covering more than 30 people, you NEED subs.
An audiotechnica kick drum mic is a good bet at about £50.
Get a few SM57's, failing that the behringer 3 pack of dynamic mics come close at £30 for 3 mics.
You won't need condensers for overheads, cymbals carry for ever up to a room the size of a basketball court.
Sm58 for vocals mabye 3
3 DI's, again Behringer
Don't skimp on leads, unfortunatly they are the most expensive thing if you buy poor quality. Buy a few 100m rolls of balanced cable and connectors and make your own, its dead easy.
With monitors, They are the wedge shaped speakers in front of the musicians, not to be confused with studio monitors which are fancy hifi speakers. 2 speakers and a behringer EP1500 will do. Everything is mic'd up through the desk and aux sends are used to send various levels of each instrument to the monitor amp so the musicians hear what they want to hear.
You probably dont need compression, but you do need graphic EQ.
But you're still looking at £3000-5000.
Disclaimer: Advice is taken at your own risk.