Will this fit......
 

Does a classic up-pipe fit a 2001+ WRX?

http://www.ebay.co.uk/itm/Subaru-Imp...item19d355be05

I'm assuming it's cat less?

Yes it will fit just make sure is not blowing as the blow at the flex joint under the shield

+1 for the above ,also the heat shields can rattle a fair bit to, so a lot of people take them off and put heatwrap on instead. You are correct they are catless
I've got one off the classic I have just broke you can have for £30 posted if your interested.;)