To race on or to train on?

Training.

part of the reason you enjoy the ride quality of the vittorias is that they have latex inner tubes; since they lose 1-2psi/hour, there's no way around topping them off before each ride.

if that is something you will absolutely not consider, then you need to write off any tire with a latex tube.

Short story is that latex tubes will ride better but you'll have to check your tire pressure every time before you ride. You can try something with a thinner and more compliant casing and a butyl tube such as the Continental GP4000s tubular but they won't last as long. Maybe try the new Specialized Armadillos. The new ones have the gripton compound and have gotten very good reviews.

Does anyone know if the new Michelin Pro 4 Tubular has a removable valve?

http://forums.roadbikereview.com/wheels-tires/michelin-pro4-tubulars-321504.html


Yes. They will lose air overnight.
Yes. They have removable valve cores.

i'm not familiar with these. but they list them in fat sizes

http://www.schwalbetires.com/bike_tires/racing_tires/ONE