Flex Pipe?

What size is the flex pipe on a 92 prelude si? I am getting an exhaust put on that consists of a high flow carsound cat., custom bent 2.25" aluminized pipe, and either a flowmaster 60 series or a muffler off of ebay because they want 90 dollars for the flowmaster one.

There is a hole in the flexpipe now so they said i need a new one, it cost $110 from there but i found flexpipe on ebay for around $22 is there any difference and what "size" would i need? i found 2.25X6, 2.25X8 or would it be the stock size because it attachs to the stock manifold? I know i should get a header but i don't have the money right now and if i can fix the flex pipe for $22 then i will but if i have to spend $110 then i'll just save up and buy a cheap header.