What's up guys. I am about to order a Carsound cat for my 95 del sol. I have DC 4-2-1 header and greddy evo catback. I think evo has 2'' pipe but no idea what size is dc header collector pipe. Can some tell me What size inlet/outlet carsound cat should I get?

and there are 2 different shapes, oval body and round body. which one fits better on del sol? thanks for your answers.