Have you considered custom steel? You can get downtubes and headtubes oversize to ~44mm, and get some nice tapered forks, 44mm will take a 1.5 external cup and 1.1/8 internal top cup, so no chance of any flex, it'll be comfortable (if you want it) and no one will have exactly the same bike.
Won't be light though unfortunately.
Hi, a friend of a friend has got into cycling and is on the lookout for a new bike. The guy is 15 stone, not fat just very well built. I believe his budget is £1500 ish. The purchase could be a frameset then source components or a complete stock bike.
Any advice?
I'm that weight and similar build, and ride an old CAAD4, so I'd recommend a CAAD10.
The worst thing about being heavy is measuring your power output, it gives way too much false hope when you see an number on the screen that says you should be winning the TDF, if only you weighed less than Froome
Actualy, that's not a bad choice for the OP either, CAAD10, and shop around for a DA9000 groupset, Ritchey WCS finishing kit and some nice-ish wheels?