The online site is not required, although it could potentially be helpful. So far, I've found Netter's flash card and Netter's Clinical to be sufficient. It comes down to personal choice. Usually, one person per anatomy group brings their copy into lab, so long as you don't mind getting random tissue/fluids on it. Personally, I have the softback 4th edition, which is still in my room in the shrink wrap.
There are copies in the library if you find you want to wait before purchasing. The variation in editions is pretty minimal, so you wouldn't be behind even if you got a previous edition.
UCLA, Engineering (2006)
AUC, Medicine (2013)