Except for some circumstantial evidence suggesting that Wonderweis is a Vasto Lord I don't think there has been much to go on either way for the rest of the espada.
Just going by their power I'd guess that 1-4 are Vasto. They were the four forbidden from using their ressureciones inside Las Noches. Ulquiorra's released form was strong enough to kill regular old masked ichigo with little trouble. Stark had been toying with Kyoraku
and Ukitake and not having much trouble. Harribel and Barragan both survived attacks which the captains were certain would kill them relatively unscathed.
Also...
Bleach 197 16 Bleach 242 09
Vasto Lord hollows are about the same SIZE as humans. When they become Arancar they have a 100% chance to take on a human appearance. Nowhere does it say that their hollow appearance is particularly human like, nor indeed humanoid, only of similar size.
Edit: ha... espada >_>