If it helps, I can vouch that the standard Remora would handle your tank size and is worthy of a few upgrades for additional performance. The Pro is rated up to 120 gallons IIRC.
According to news reports, the "S" distinction indicates presence of a new (slightly) higher-flow design, including in your Pro's case a Mag 5 pump and larger mixing chamber, among other mods.
A Remora Pro would kill on that "little" tank...
If the Remora seems too small, I'd say go for the Pro!
-Matt (Sporting a classic AquaC EV90)
P.S. Sorry no direct experiences to offer, but I can tell you this skimmer is a safe bet.