Your best bet for wheels are either Primo Hula hoops or Odyssey Hazard rims, get them in chrome so that your brakes are top notch, go with 48holes if you worried about strength.
Hubs whatever you can afford; maybe a freecoaster and a sealed front hub.
The Nankai freecoaster and the new Odyssey Reloader hubs are pretty much the favourites, there is a cheaper alternative the Taska or Generix freecoaster, but i dont recomend those...

Tires: cant go wrong with Primo Wall tires or even Primo Vmonsters (nice and lite). Wall are tuff as hell and last ages.

The small sprocket thing has been around in flatland for ages, but has only sorta caught on recently with street and park.
If you go for a freecoaster hub look for something with a 12 or 13tooth cog, then you can run a 30 or 33t up front, doesnt get all that expensive that way. (i currently use a Nankai coaster with a 11t driver and 25t front sprocket)
If you going for a freewheel hub; a flip flop hub with 14t / 16t threat option is the way to go; get a 14t freewheel with that and anything around 36t to 39t in the front side.
try : http://flatlandfuel.com

Hope this helps