Fltr:
@smet
We hope to find somebody that sells such balloons. Otherwise we will need to construct ourselves (perhaps with some help of people that have launched balloons before), which could be diffcult.
Buying the balloon is not difficult, but you need to know what type to get, how big, how to attach it all together and fill it.
I would not be expecting someone selling balloons to provide all the neccessary advice and guidance for free.