My meth injection kit arrived today

.. I have 2 questions I'd like to ask..
1. What psi will be best for the boost controller to be set at? For the meth kicking in? It's set at 10 psi at the moment.. It's a 1.8t about 230-50 bhp and 250-300lbft (will be having it mapped in eventually)
2. Is eBay the best place to get meth from?
Cheers in advance for the help