www.tsiscooters.com, I think you can get them up to 24 high, but he'll definitely make them taller if you just email him. Be aware though, bars that tall can get pretty weak...
If you want custom-sized classic "T" bars, get them at C4 *www.c4scooters.com)....just send them a note if you can't find your size on the website. They are awesome bars...been riding mine for a few years and they are still going strong. Used other make bars but come back to the C4s as they feel just right.
Raderalls are stock at 24"H. can use scs to get up to 26".
But yeah freestyle depot and scooter zone usually have raderalls in stock. only thing is i don't think they have hic right now.