Super Gloss and Spot UV are coatings that leave a glossy finish.
The main difference is the application - Super Gloss is applied as a flood, which is throughout the entire surface, and Spot UV is applied to specific areas only. See: What is Spot UV?
Super Gloss is available on a variety of stocks from 15-22pt thickness. Spot UV is only available on 20pt and 26pt Silk Matte.