I took my Bristol 30 from Fort Lauderdale to St. Petersburg last May. It's a nice sail up to Stuart on the outside, but read up on the inlet there before using it. The sands shift, and it can be tricky. I followed a local boat in.
The Okeechobee Canal is easy enough, pleasant to do once. I singlehanded the locks without much problem. Kind of fun to motorsail on the edge of the Everglades. Takes about three days to motor across. Not much on the canal, so be well-supplied.
If you decide to take the Gulf Intracoastal, there are only limited opportunities to sail and lots of drawbridges. Sailing or motoring in the Gulf is faster and better. With good weather, you might be able to anchor out in the Gulf at times and avoid ducking in and out of inlets.
You have to figure 40 or 50 miles a day if you're anchoring at night. Of course, sailing straight through would get you 100 miles a day or more in the Gulf, if you can handle that.
Very doable, if you have the time. A fun trip, I'll bet. Try to do it before the summer thunderstorms and 90-degree heat set in.