Skip the gin pole and use a 6' step ladder if you are worried. It will raise the mast to an angle that you can crank up the mast straight from the mast stand winch; simple.
I didn't say a spinnaker boat had to be an F18. However, the class has been around long enough that you can find 'tired' but functional boats for a decent price. Most of them will come with and are engineered to fly main, jib and spinnaker. You worry about gin pole loads. I worry about loads on boats that weren't designed to carry "add on" equipment.
Skip the starter boat! I often sail my Tiger solo and not rig the spinnaker. Since the jib is on a furler, that makes it even easier or I just leave it rolled up. I have yet to rig the jib on my F16 and main/spinnaker configuration is why I bought the boat. My F16 main alone has the same number of lines as my Hobie 14. It doesn't get any simpler than that.
All that said, if you have the funds, a multiple boat program works the best.
--
dk
Blade F-16
Hobie 14
Corsair F-242
Mirage 25 (Sold)
Hobie Tiger (Sold)
Hobie Tiger (Sold)
TomCat 6.2 (Sold)
--