No prob (you can always add to my reputation, click the scale

).
No EML with 200 cells cat, I had one when driving decat, but that was solved using a lambda spacer. I think I know which DP+cat you are referring to, but it might be best if you posted a link + picture.
Bigger DP will give noticable gains, dont know if the cat is any good. The Magnaflow I have, is also used in the 42 Draft Designs downpipe.