for me, Wiseco is the only place to buy pistons. just an opinion though.
as to the compression, you have to do that by modifying the cylinder head, or purchasing a new one altogether. do a search in this forum for more than you will ever need to know about replacement heads, and head modifications.
to port/polish, thats a serious question. with so many shops doing these services now its really impossible to say who is the best. but from reading what others have written, and from my own experiences, just call several builders and see who you seem to like the best.
but a few places to start:
Patriot R(acing)
Passion R
Trinity R
A&S R
Grand River R
Ohton's
Tyson R
Packard R
F.A.S.T.
Rick Cairo
excuse any others ive left out.