I tried the IDM EVO3 with both the Mega 2033 and Novarossi 2052 pipe, both with medium headers, and was really dissapointed with the 2033... BUT, my 2033 is allready a bit older, maybe there is something wrong with the pipe.
I ran Mega DSII (which is almost the same as your IDM EVO2) with Novarossi 2052, and the engine will love that pipe.....
I also hear good things about the Sirio 2013....
Most of the people out here in the Western USA are using the Sirio 2013 pipe and seem to like it best.