ok... $200 US...
This is what I think would probably be best.
I would recomend getting 3 boxes of Infantry, a Heavy weapon box, and whatever bits you need for your HQ. You can EASILY get 9 heavy weapons out of the heavy weapon box with no converting. I just use normal Guardsmen with either LP/CCW or grenade launchers in my HQ, and either schaeffer or a cadian Lt for the Officer. If you want plasma guns, that'll set you back a bit more. That'll set you back about $100 US (very rough, as I live in Aust).
That'll get you your 2 troops and an HQ. If you want, you can get a Chimera, so you'll have an AF squad, and a platoon w/ 3 inf squads.
Then, maybe get a Russ and Griffon (deffinatly griffon
), some elites, maybe Hardened veterans, though they require some converting, or Stormies, or my favourite, Ratlings.
Ratlings would be by far the cheepest option for elites, as for $44 Aust (probably about $20-25 US) you get 10 rats, compared to two times that for stormies.
Fast attack... don't have to have any of this, though I often use sentinels with Lascannons for tank hunting. A Hellhound looks very tasty, though I haven't gotten one yet. Rough Riders also look tasty, though I hate the models
Use something like Fantasy Empire Knights or Bretonnian Questing Knights with a little converting.
Hope that helped.
Eller