With either of those two alpha engines your best overall performance and economy will be had with the a plus 0801 pipe and a p3 plug. You can get away with using a OD97T plug if you want to save a little coin but the p3 is a little better IMO!
Let me know when the time comes I have the Alphas in stock along with the pipes and haven't gotten the B6's in yet but they are only a phone call away!