Here's the SuperFlo brochure: http://www.pentairpool.com/pdfs/superfloDS.pdf

I checked prices on both a replacement 2-speed motor (~$300) and a complete new 1HP 2 speed pump (~$400). For that difference, I'd recommend replacing the pump, and saving the existing pump for spare parts. There is a new issue this season: Pentair has shortened the warranty on equipment sold directly to the user, so . . . install the pump IMMEDIATELY on receipt. Most likely, with a small pool like that, you can leave the pump on LO, except when you are backwashing the filter. Links below. The pump below is listed as having a switch on the motor case, so you may not need any wiring changes. But, I've also listed a DPDT switch of the type you'll need for external switching.

Pentair SF-N2-1A SuperFlo Energy Efficient Two Speed Inground Pump with Switch, 1 HP

Eaton 7810K1 Extra Heavy Duty Toggle Power Switch, AC/DC Rated, Screw Terminal, On-On Action, DPDT Contacts