My 17TL has Konis front and rear and IMHO they are "fabulous". Everything just feels "tight".Can't remember how much they cost, they went on over 10 years ago and still feel like new.
Konis are now unavailable for the 15/17 new. Fuego rears (Koni still available)will fit straight on the rear of a 15/17 with similar valving and compressed and extended lengths within a few mm. Fronts may be able to be bought from wreckers, and seals and such are still able to be bought to repair them.