Most people on this forum are complete nerds and never had some good pussy so they will flame you just because they think they are better than you and because they don´t want to see no one do better things then them.
So here you go. YOU and only you have to decide wheather to keep or get rid of your D15B2. IMO you should get rid of it cuz parts like Forged rods and other things are more expansive and hard to find. So I would go D16Z6. Then if you want to go full out. I would Bore the block. At least to 78mm, I did 80mm but if you want to be safe then just do 78mm, Deck your block, mill your head, Bigger valves, Bisimoto cam ( at least stage 2 ) valve springs and retainers, Some bronze valve guides while your at it, Port and shim that oil pump, Get a cam gear to fix your timing since your going to mill the head and shit. Get a eprom burner and a chip. Get a basemap.... burn that chip and throw it in your new ecu. Go get that bitch tunned and Post pictures of every thing you fucking do from tightening bolts to taking a shit brake so people here wont call you a lier.
Holpe I´ve helped