clarification
 

Okay, where could I find an upgraded ECU, lightweight clutch, mass air flow sensor, big bore throttle body, and connecting rods? Sometimes there's websites out there that have parts like this for other cars... but then again, usually they're honda parts.

I think this is sorta funny though, a question on where people get their parts from and then the person asking the initial question gets asked questions and no answers. I did not set a specific budget, just wondering where the suppliers are. Im just curious about ballpark prices and where the parts can be found.

FVD USA, among others, does everything. Parts are available.
Without a budget and knowing what you are planning to do with the car..race? track days? there are no answers.

As Britwrench pointed out, The sky is about the limit on performance products for these cars. You can spend $4k on a nice intake and exhaust, you can spend $35K+ on a performance modded engine... A question about how much you are willing to spend enables us to give you a point in the right direction. It isn't being sarcastic or flippant as you seem to imply by your post, rather a solicitation for more information to better answer your question.

AFJ