Locky, if budget is a concern and the wet end of your pump is fine, I wanted you to know that it is possible to replace just the motor with a variable speed made by Century (formerly AO Smith) called V-Green 165. Cost of the motor is $399 at
Swimming Pool Supplies - Pool Parts - INYOPools.com and their guys will help you get the right variant if you give them the serial number. (You need to know square flange or round flange.)
My cost for electric is cheaper than yours at .17, and I saved about $60 each of the last two months since installing it over last year's bill -- ymmv as I run my pump continuously, which is viewed as unnecessary here...(If you're curious, I do it because I get a lot of debris in my forest, am on well, use sequestrants which increase spent phosphates, and I run my heater a lot...plus now I'm operating in winter in a dome and need water to mve 24/7). in summer, it is not necessary to turn the water this much but I simply prefer to and with these considerations, my approach makes sense for me, though others would say I'm nuts
So a vsp was a no-braner for me. In Cali, I thought they've actually banned single-speed...requiring vsp on replacement.
Hands down you should go with vsp over 2-speed. With 2-speed, if the low speed is too low for your swg and heater, you've got nowhere to go...but with vsp you just bump it up

- The savings are pretty dramatic even if you only drop down to 2850 or 3100. And with solar, future gas, and swg, its difficult to predict what flow you'll get because each pool is different depending on feet of head.
Ps. From my product research earlier this year, Superflo does not get a lot of love from pool techs and others in the know. I'd steer clear when there's a cheaper option...or go the other direction with intelliflo, which does get a lot of love

I went with the cheapest option because I wanted something that fit the same wet end so that if I had a pump failure in winter I could just swap my single speed back in if I had to race against the clock on pipes freezing...so the retrofit made perfect sense for me!