Steelix might be someone you can use, you get an Onix in a trade too so he'll be easy to train, although finding a Metal Coat can be a pain (use Thief on Magnemite or wait until you go to Kanto, or trade one over if you can). If you can wait for a while, Mamoswine is a nice option for a Ground mon.
Try using either Miltank or Tauros, they are very strong attackers and can learn pretty good moves.
For a flyer, there are a couple options. Crobat is prolly the best one, and Murkrom/Honchkrow is also good. You won't be able to evolve him until Kanto unless you trade a Dusk Stone over though. Skarmory is a late option too. (Only in SS).