I looked for Sebring, Remus, Supersprint exhausts.
Sebring and Remus has only one type that fits Seat Ibiza 1.8 20VT and they're both DTM look (two round pipes - like Miltec).
Supersprint is the only one that has oval one + it also has the pipe which replaces the middle 'pot' - that'll give you some sound!
I recomend you Supersprint - the prices for all are similar.
I can't tell you anything about miltec since I can't get it in my country, but I know it doesn't look as good as Supersprint since it is not oval one!