Which Header???

Ok, I finally found a catalytic converter that fits my 99 hatch. I found that OBX and Ractive (Toucan Industries) both make one for hatchbacks. Which one should I go for? Any opinions? Both make a variety of other products but I havent heard anything about their catalytic converters. So which one?! Help!

Ractive:
http://www.seffects.com/catalog/products_by_manufacturer.asp?Manufacturer=RActive

OBX:
http://www.massivemotorsports.com/main/obxexhaust.htm#cat

Now the question after deciding on the catalytic converter is which header should I go for? I need one that can take two oxygen sensors. HP Racing? Landspeed Racing? I saw on Ebay that Ractive makes a header that has 2 oxygen sensors sockets. Any other suggestions?

My last question is will the catalytic converter and the header still fit with my Greddy SP exhaust? Any help will be greatly appreciated!