Sorry that it took me a while. To buy a stick in Basel is actually impossible, but Julia from the club takes orders for stuff and delivers it to the Training (see http://www.fastplay.ch/
for what she sells).
The best way to go to the pitch from Gundeli is taking the bus nr 36 to Tinguely Museum and then change to the bus nr 31 to Sportzentrum Rankhof.
Hope this is a help and not too late.