Couple things:
-The Nashbar Prima 2 seems to be a rebranded CST C740.
-Vittoria makes the Zaffiro in 27x1 1/8 and 27x1 1/4; Niagara has them.
-There are a couple of cyclocross tires available: the Tioga Bloodhound and Club Roost Cross Terra are both available in 27x1 3/8. Again, Niagara stocks these.