[JPhillips]

Take a look at the Shure PG58 mics. They're good all around mics and should be pretty rugged. You may spend a little more, but if you buy shitty wireless mics you'll wish you spent a bit more soon.

I'm generally not a fan of powered speakers, but that probably comes from me doing most of my sound work fifteen years ago. Powered speakers would probably be easier for you and quality has improved a lot.

If it's a choice, buy a little more than you need. Don't go crazy and buy a 48 channel mixer, but having a bit of spare capacity will likely be beneficial sooner rather than later.

I'd also at least look at local stores with good reputations. You are likely to need rental equipment from time to time if your business takes off and having a solid relationship with a local dealer will be important. Check prices and get advice, and if you can't get a good deal do it yourself.