Hang out at your local races, and see what the Cat1/eloites are using.
I can tell you what they use by me. If they/their team has a tire sponsor, that is what they are on, otherwise most I know that buy their own ride vittorias or veloflex. And most race on tubs anyway, but if going clinchers I'd recommend veloflex corsa/master with latex tubes. If not on tubs, I use that combo on my clincher setup for training and it is race worthy. Off season I go with either gatorskin or paves, and have some veloflex arenbergs aging that I will try out for next spring classics.