I would generally concur with Joshua with the caveat that, in my opinion, Epicureans would want both stability and freedom which is a difficult balance to achieve. So, I'd have to posit that they wouldn't want a totalitarian form of government that requires conformity among its citizens. However, I find it hard to think that they'd prefer a full true democracy (albeit without women, slaves, etc., participation) like ancient Athens where political positions were determined by lottery. I could see them being alright with a benevolent monarch but then you're at the mercy of who's next in line.
It's a good thought experiment, Cassius . Those articles and papers on Philodemus and Epicurus are tantalizing. There's not a lot to go on.