They are the same thing. Tris HCl has a lower pH. TRIS is more basic. So if you try to do an acid buffer with TRIS you will have to add HCl to reduce its pH. So actually Tris HCl is TRIS with some HCl added in order to me it more acid from the start and ease the preparation of buffers. 

Tris pH 7.5

Its pKa is 8.1 and the useful range is from 7.1-9.1. Make sure that this is the right pH range you need.