To convert Fiat to BTC I mainly use Coinbase- there are a few others but they are far smaller and less reputable; unfortunately I think we need to stick with coinbase for now, but once you have your BTC I'd suggest sending it to your own wallet or to an exchange if you want to trade or buy other alt's- coinbase is really only good for moving fiat to crypto or back if you need more fiat for something.
RE: Bitcoin bear market, short and long term price targets