offer, I listed the mods on my comment ^^^well the b18 will be much easier but here is a great site.
http://hmotorsonline.com/
p.s if your intrested in selling your Y8 LMK.
K swap is the best thing to do. Next would prolly be the b18 because of after market support and not a very hard swap to pull off. IMO I think the H22 is better than a B18 but it's a harder swap to pull off, even more so if you want to keep a/c and the aftermarket isn't so great.
This all really depends are the real goals you want.