Mirroing do you have any flow bench sheets to back up those claims? Not saying your lying, just having a hard time believing your home made port and polish has your LS head flowing at the same CFM as one of the best flowing Honda heads. The biggest issue with LS heads is their lack of flowing. Its been said over the years that even a port and polished head will still not flow as good as a stock b16 head. Thats one of the reasons people go LS/Vtec is to have the better flowing head (aside from vtec)
I would call local machine shops and ask them if they port and polish, be sure to ask if they use a flow bench. If they say no, then look elsewhere. Without a flowbench all your doing is gasket matching which isn't going to do a whole lot. Some people will do it "by eye" which is a big no no. You can actually take too much material away and hurt the flow of the head, plus you gotta watch how much you remove so you don't get into water jackets and stuff. Also ask them if they are going to blend the bowls at all or just do the intake and exhaust ports.
A port and polish is usually a 5-600 dollar investment. There are some really good well known companies out there, but you gotta pay to play. PortFlow, Endyn, Headgamez (I think thats how they spell their name) are all good companies that do headwork.
My GSR head was done by Pure Tuning here in Ohio and looks good. I wish I had flow bench results but the kid I bought it off of couldn't find them. The biggest advantage of a port and polished head in my situation is it will help spool the turbo a few hundred rpms sooner. On an NA car its a nice improvement power wise as head works is where all the power is gonna come from anyways, the bottom end just has to hold on for the ride.