Update: didn't find a place in Tampa area. Now back in the sunny PNW
Tampa/ St Pete's had plenty of plastic "family" and fishing kayaks, SUPs, etc. but no skis. Having said that, there was wind but no waves, so a ski would be nice for fitness and exploring the waterways but nothing really "technical" from what I could see. I ended up SUP-ing, and that was great for getting out on the water.