I think the more services and items you can purchase with BTC the better.... But the particular topic you're addressing is one that really needs to be handled by people who are passionate about it, rather than someone looking to make a quick buck by offering legal drugs before anyone else. Sourcing is hugely important, and too much profit motive here equates to subpar quality.
I'd say figure out what you and/or your friend are really interested in, and build something around that. The market for BTC is so new and open, don't waste the opportunity to do what you like!
I'm really interested in running miningfarm #2 software but so far little money has been generated from that, my business partner is highly enthused about this idea that he has; Especially since he's experienced this credit card fraud problem in the past first handedly. He just wants me to do the website/system admin and he does all the etheogen selection. The business proposal is from what information I was able to understand from his idea.
I assure anyone that the main intent isn't to get high
I've have the honor of watching his spiritual rituals and as odd as they may be I'm kind of starting to believe in it a tid-bit. Of course people will want to get high but from my partners experience is "with a spiritually bad intent with the use of these ethogens comes with bad experiences" which to me means that if you take them to get high your going to fall in a world of hurt because you don't know what your in for. I believe it too I've seen how much time and energy he displaces to be respectfull to that which isn't physically here.
Thanks for the input guys! keep'em comming!