The Hyperlite 2 custom you can only customize colors and body/arm size.
The Hyperlite 2 Pro custom you can do the above + get the options for reinforced shoulder floaters, reinforced bicep protection, reinforced forearm protection, custom wrist length, and arm type (Hyperlite2, Hyperlite, Mach, or Supreme Pro).
Edit: Order your custom from a Canadian shop (like The Goalie Crease) and you can save yourself approx $100 with the conversion rate vs Pure Hockey, even with shipping.