I belive the board is a complete drop in, dont think there are any more boards besides the was and the blackhart, at least not now anyway there used to be more e.g. the predator board and others. i say go with the blackhart for your secound imp as it is adjustable and cheaper then the was. regards to your question about screw and oring kits you can get adrenalin ss screw set and orings but other then that sorry just smart parts.
and if your after a prv (burst plate or as known pressure release valve) pm tom allen belive he had one although dont hold me to that, if not you have to ring sp.