I'd get a custom carbon Ruegamer Uberlight frame. Unfortunately the woman who made them has quit doing frames and in any case the special tubing she was using ran out.
On it I'd have a custom selection of nice light but reliable parts, and a set of Lightweight carbon wheels for races.

Failing that, a Cervelo R3SL with a custom selection of nice reliable parts and some handbuilt carbon wheels. That one I've already got.