Magnaflow Exhaust - need to pick freebie

Alright, I'm looking at picking this up for my 98 GS. http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&rd=1&item=7950204795&category=33630&sspagename=WDVW

Seems like a decent deal to me, but I need to choose one of the following:
High Flow Catalytic Converter
K&N Replacement Air Filter

Which would you guys go with? I assume the high flow cat converter.

go with the cat. that way, you can have it replaced while the exhaust if already off, and can easily be mated to the new piping, plus, its already up in the air.

I dont know if id pick a magnaflow exhaust, for one im not sure the design of the muffler allows as much flow as a can type muffler, and two is that i had thought about gettin a magnaflow exhaust for my rs but heard one and in my opinion it rattled, was quiet and just didnt sound that good at all. Go to magnaflow.com and listen to their sounclips if you havent already and see what you think. I got a nice tsudo exhaust on ebay for like 250 and love it.Thats just my opinion on it, peace.

I just know that there's a lot of mufflers I've heard that sound like shit and I don't want to be one of those guys with the annoying muffler. I've never heard bad things about the magnaflows.

Ive got a magnaflow exhaust on my car (civic si not an eclipse) and I think it sounds great. Its got a nice low growl that doesnt get too loud or annoying. Also Id go with the cat as well just because your already going to be under there anyway.

get the cat.
magnaflow will work fine. the sound is all preference. magnaflows are much smoother and quieter then ricer cans but they are still louder and growl more then stock.
shadow eclipse: a rattley exhaust is caused by crappy mounting. occasionaly a old muffler will break inside and rattle but on a new exhaust its just mounted wrong

ive got a magna flow on my 95' GST and i like it, cuz i really didnt want some honda civic bean can stuck on my ride, but im glad i got the magna flow cuz it's got a nice low growl to it