Why go below 36?
Weight and aero savings are minimal, but you get a BIG reliability improvement.
RimS:
Mavic
http://www.mavic.com/en/product/rims...on/rims/CXP-33
or cheaper alternative:
http://www.jejamescycles.co.uk/rigid...r-id51460.html
Plus decent spokes (like DT Swiss)