Order from seedboutique.com

They're slightly cheaper than ordering straight from Nirvana and you can get Nirvana's seeds there. As far as the self pollination, just make sure you give the plants a completely dark 12/12 cycle and you likely won't have pollination problems.

And about pollinating part of a plant and not the rest, yes you can do that. You need to be very careful though as the pollen can easily go through your whole room and pollinate the whole plant Do some reading up first about it.