You aren't going to get this, or even close, without a totally new aircraft.

You would need something like the Ryan Vertiplane here with it's ability to redirect the air totally downwards from the prop blast.

Conventional flaps will help with the takeoff but you can do the same thing by just building a super light old timer design with a strongly undercambered wing. For example I have an 84 inch Flamingo with a .35 on it. AUW of 5 1/2 lbs. In a light breeze the takeoff roll is literally about 10 feet to a 30 degree climb.

If you want to experiment further with the existing model try slotted flaps. Roderick, the split flaps you suggested are mostly good at adding lots of drag along with some lift. For more lift with less drag the slotted or, better yet but a bugger to build, full spec Fowler flaps with the intermediary director flap are better for adding lift with less drag. You'll have to build the flaps up as small airfoils though. Just a flat plate won't do. And the tracks to position them are important too.

Good luck.