Another vote for AeroTech. And Pearl's Select (?) line offers a bit more room.

But, really, the best advice is f*ck it. I'm a bit over 6', have it down under 270 for the first time in eons, but since I got back into riding a while back I was instantly comfortable in lycra. No one gives a rip, and you will be surprised by how many riders out there are SuperClydes, and they don't give a rip, either. Tight is comfy and efficient! Wear black.