Nowt wrong with bivy bags, I've two surplus MVP bags from Endicotts for my lad and me. Used with a small tarp or poncho setup they're great. Not as comfy as a hammock, but will provide a better nights sleep than just using a tarp/sleeping bag/ground sheet set-up as the bivy bag stops any breeze/drafts from reducing the insulation of your sleeping bag.
To be honest, the bivy bag and tarp set-up is now my second favourite after the hammock now, a tent comes in third unless the weather or midges are really bad.
In your position, I'd go with Humakt's offer. I might have done so myself if I hadn't recently bought a second bag.
Al