RE: Veloflex gumwalls.
The veloflexs are incredibly fast feeling tyres and together with lightweight latex inners, are the closest thing you'll get to the ride of tubs (says a guy who has'nt ridden tubs :S ). For minimum weight I run a master (20mm) on the front, and for slightly more longevity a Pave (22mm) on the rear. for a 'non-workhorse' bike, I really cant recommend this set-up enough.
http://www.veloflex.it/catalog/master.htm
http://www.veloflex.it/catalog/pave.htm