you can get quantums from planetfootbag.com. the german division doesn't have many sizes left. austria still has most of them but shipping them to germany is ~ 13 euros.
Alexander Trenner
footbag-vienna - feel the spirit
if you dont get the quantums in your size and you have paypal, look for the adidas rod laver mesh on ebay.com. a very common shoe for freestyle. the reebok g-unit g6 1 is what ive started with, definetely a very very good shoe for freestyle (easier stalling). they got some on ebay.de as well. or you can wait for the quantum 02 they realease in spring. the shoes u got now are bad.
Technically you could mod the hell out of those and play in them, but you would be muuuuch better off getting something more appropriate. The shoes that have been mentioned already in this thread and for sure your best bets.
You seem to have alot of potential, don't hold yourself back with crappy equipment!