I wrote something earlier but forgot to click send. Oh well. I agree with the others on this topic.
I'm an instructor and 4 hrs on a trainer is crazy, especially if it was windy enough for you to fly an inflatable. Well maybe it was a good thing in the long run.
Here's the good part, you spent a lot of time flying the kite. You flew different kites with an instructor and you have spent plenty of time with a small inflatable in 25 mph winds. The bad part is that in the 6 hrs with your instructor, you didn't attempt to water start or at least try to put the board on your feet to see how difficult it can be. At least you didn't say anything about water starts.
You owe it to yourself now to go back to some more instruction. You have a lot to bring to the table now. If you end up flying the kite some before taking another lesson, see if find yourself able to tell where the kite is without starting at it the whole time because your next hill to climb is flying the kite while trying to get your feet in the foot straps.
Your next instructor should be able to confidently have you flying the kite with one hand, board drag upwind in no time, and proceed to water starts very fast. In the long run you may have saved some money but taking just one lesson and flying yourself bored in your free time. Now you will be able to focus on primarily getting up to ride!
Contact Endless Windz, I think they are near Orlando. My buddy Mike who I coached in snowboarding and taught to kite and trained for teaching works for them. He's got a huge quiver to work with, all the way up to a 17meter. Send me a personal message on here if you want his contact info.
Sell the 2.5 to that other guy and put the money towards your lesson.
Have fun.