for what you mention there you are going to need either a huge amp to run your 4 bass bins or at least two 2.4k amps.

same again to run your tops/mids.

an active crossover. shit loads of speakon cables and xlr's
if your doing outside parties you will also need at least 7 or 8kva of generators.

thats just for starters.

have a look on ebay. you often get good bassbins on there. (precision devices are the bollox)

behringer do a 2.4k power amp at the moment for under £200 aswell. i got a couple of them and they seem pretty good. a mate recomended them whos used them for a few years with no problems.