Yeh I agree, you should be cruising in no time.
In saying that, a few ex-windsurfers over here have traded up and currently trying kiting with little to no progression so far. Their kite spends more time in the water than in the air.
Did you fly a 2 line stunt kite when you were younger? Have you flown any steerable kite before?
If no, then you may struggle at first. Or you may be a natural. It just differs for different people. Somepeople are useless, and some are ace.
Remember, its 85% kite, 10% board skills and 5% balls.
You should be able to fly your kite with you eyes closed, and still be comfortable and in control.
If I were you, I'd be looking at a brand new Slingshot T3 11m. Soooo cheap and its got the best safety on the market. Plus a great warranty.
Otherwise Best Waroos are cheap, and 07 Rebels are cheap now too. The T3 will have much better windrange and relaunch tho.
Board wise. I'd buy a cheap 2nd hand 140+. Bigger the better when starting out.
Then when you have it suss, buy an 07' 132 or 135. (check out underground FLX)
Oh yeh, and do you have a 'V' ironman chest on ya?
If not you might benefit from a seat harness. But you should already have one from windsurfing anyway. Just check its not rotten from 20 years of sun and salt.
Good luck!!
ROFLMAO - Doc you have waaay too much time on your hands. That's a bloody huge post!
Grahamette, this ex sailboarder managed to get up on the board after a few lessons / sessions totalling about 3hrs.
Without lessons it would have taken a lot longer and my confidence would have been destroyed through crashes.
Getting up is the easy bit and upwind will be a no brainer for a sail boarder but from that point it gets a little more difficult working out transitions, stance and good kite control
After your first few runs you will wonder why it took you so long to trade the sailboard for a kite, there's no rig to look around or through, if you fly the kite high and wear sunnies you won't see the lines or the kite and it feels like you're blasting along with no motive force !
Go for it 
