I have used PB2 successfully for a peanut butter porter.
Use two jars of PB2 (some GNC carry it, but check first), in last 10min. of boil...
I had no head issues with the beer, but I did add .5# of instant oats to be safe. Oils were never a issue...I made sure though I got all the PB from the boil kettle into the fermenter...let it sit for 4 weeks, cold crash and racked off...
You might want to use a hop sock to keep the hops separated from the trub going into the fermenter...
The PB will come through as the last part of the taste...if you want it more forward add 1oz./5gal of PB extract (cake supply stores or ebay).
Hope this helps...