Out of those two, 350Z is much better looking (IMHO), faster, more conventional to maintain but the road tax is very expensive.
I suggest Nissan Silvia S15 Spec R is a better choice than those 2 if you have to have a sport coupe. But if you're ok with a sport sedan (4 door) as long as it's fast, then the Lancer Evolution is the best choice. With 80K d/p, you can try to look for Evo IX 2006. It's much faster than RX8 (maybe even the 350Z as well), still conventional engine to maintain, 4 door practicality, safer handling especially in the wet, and much cheaper road tax than the 350Z.
I suggest Nissan Silvia S15 Spec R is a better choice than those 2 if you have to have a sport coupe. But if you're ok with a sport sedan (4 door) as long as it's fast, then the Lancer Evolution is the best choice. With 80K d/p, you can try to look for Evo IX 2006. It's much faster than RX8 (maybe even the 350Z as well), still conventional engine to maintain, 4 door practicality, safer handling especially in the wet, and much cheaper road tax than the 350Z.