muffler question

ok ok i kno this is retarded n i could find out the hard way but i'd like to kno b4 it happens. here's the story pretty much my stock muffler got thrashed so i took it off n hey i liked the sound...well my dad seemed to i guess notice it n was askin where my muffler went so i told him it got stolen. so he wants to get one b4 i get pulled over n blah blah blah. i keep showing him performance exhausts like the apexi n1 not that i'm gonna get that but i showed him that n he doesn't seem to understand that it's a muffler, he wants to get a flowmaster 40 or somethin like that cause he doesn't wanna spend over $100. i read about it and it says it sounds good but i don't think it'd sound good on a 4-cyl right..only 6+. but anyways i find cheap ones on ebay like this http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&item=2469187426&category=33636 .. just an example and i was wondering if it was more worth it to get one like in the link or that flowmaster shit..also not dealin w/ the main point but would an exhaust for say a 94+ teggie fit on a 91? i'm sure it does right? yeah you guys should remember i'm not the brightest one nowadays so any stupid questions i have...don't hate lol