CEX.io is the best right now. You'll pay a bit of a premium, but no term, easy resale, and instant mining.
The website seems complex.Can I buy Ghash at any rate I set?I can even set 0.001 BTC per Ghash.Is that real?
if cex.io is too complex, then renting is not for you.
anyways, renting GH is not a very great idea, almost certainly you will get less BTC back then you put into it