from what i;ve read, i think the 1.9 JTD is a great engine. alfa even borrowed it for their diesels! search "Fiat Stilo 1.9 review" in google. it comes up with professional review as well as customer ones!
i quickly just checked parkers reviews, the 1.9 JTD came in 4 varients, 80bhp, 115bhp, 120bhp and 150bhp. go for the 150bhp if you can afford one. it only came in 3 door. beware the 150bhp sporting was only produced from july 06 to dec 06, just because it has sporting badge doesnt mean its the 150 bhp engine! the log book wont state what bhp it has either.