My advice: if you're just starting out, buy a complete for like $500 from someone like Fit or Sunday, and gradually upgrade your parts over time. Definitely run a back brake. Going brakeless is just a trend and all you'll do is eat up shoes trying (failing) to stop. When the time comes, the first thing you'll probably want/need to upgrade are your wheels (rims, hubs, and tires). Spokes don't really matter unless you're a weight weenie, so get whatever is cheapest. Start out by learning to hop really well before you start hucking yourself all over the place. Then learn ones, tire tap 3s, and eventually hop 3s. If you have a small ledge or something around, learn feebles, they're by far the easiest grind to learn. From there you can learn stuff like bars, tailwhips, opposite spins, etc. It's really endless. Just mix it up and have fun. BMX is awesome.