These pedals will thread into your cranks just fine. However, I wouldn't pay much for them just because they are Campy. "Triomphe" was one of Campy's lower line groups and these are nothing special.

As to e-bay, be careful. Sellers often badly exagerate the condition of their items so be sure you can return them if the bearings are bad or something else is wrong.

BTW, have you checked your LBS for clip-and-strap type pedals? The may have some NOS good quality pedals at give-away prices since the demand for these is now so low.