I'm down for 4 as well if I may join.
so we need know 9.5btc more
According to Jani, only one person must contact him for the whole group of 20 btc.
You guys don't know each other, how and who will manage that?
Probably, you should find an escrow for that purpose.
i dont see any problem. one person can contact him via email and put our all emails into cc.
escrow dont needed because everyone of us can send the btc directly to jani.