If you only want to run a one reg system, then you would look into the Geddon or Max Flow.
If you don't mind running a dual regulated system, then the gladiator/conquest combo is a popoular choice.
If you want to go cheap on a dual regulated system, get a regulator and a preset. Most people go with the gladiator/sidewinder or any other number of reguators with a preset by pure energy or crossfire.
Personally, I run a Max Flow with a gas through grip.
Hope this helps.
Bring the enemy to justice or justice to the enemy. Either way, they're dead.
May God have mercy on your soul because I sure won't.