Alky is definitely only as reliable as you tune it to be. That said, there are plenty of play bikes on alky in the dunes. Quite a few guys here run nothing but alky in whatever kind of bike. You're gonna have to call a few builders to see what package they feel works best for you. Pipes will have to be some type of in frame drag style. Shearers, snipers, CPI, hand made .......
Carbs 35mm and up. The chassis, well obviously good arms and shocks. Minus 2 swinger for trails FTW!