lelobysfoot, here's some 'which tubs' advice from a useful bloke on the Serotta forum. He's American and goes to Belgium and Holland to race quite a bit:
You can order Vittorias at $45 apiece from various English mail order houses. Get a couple other people to go in at 10+ tires per order and the shipping isn't bad. The Veloflex is definitely the nicest road tire out there, and these days I'd include the Dugast in that listing. You can always buy an FMB road tire, but why? Veloflex is worth the money. Can't remember the last flat I had on them, the ride is fantastic, they stick well in all weather conditions, and ... you'll just love them. Buying otherwise is like getting a decent sports car and then putting on some cheap Michelins at Costco. As long as you don't flat a lot, you'll get the value out of Veloflexes. Otherwise, the Vittorias are a close second and a much better price. Even the Vittoria Evo Pave tubulars -- big, resistant to cobbles and everything else, but a nice ride -- are only about $55. If they weren't green, they'd be perfect.
And here's some rolling resistance info for you, courtesy of Jobst Brandt:
http://www.analyticcycling.com/ForcesTi ... tance.html
For more advice on tubs I reckon the best place is the weightweenies forum - have you been there? Full of Yurpean racers who use tubs a lot.
Have you tried Mike Dyason? He sells some useful odds and ends www.mikedyason.com
Edit: I see everyone knows Mike Dyason already!