I have a bud who has an extremely fast and versatile speed freeks force. Generally he fields a handful of buggies with a variety of weapons on 'em, in squads of 1 or occasionally 2. He also as a looted tank or two, some deth koptas, and some bikers. He generally saves Trukk Boyz for bigger point games. Everything in his army has an AV, and can usually tackle light vehicles.
I don't currently have an army, I'm about to build one, so what do y'all recommend? I'll probably field some sisters, Zealots, and Arco-flagellants at the least, with perhaps some Seraphim and Penitents at 500+.
How would I beat it?