Id take it out for a drive mate see what you make of the 120, it will feel slow compared to the 180 and needs to be reved to get power out of it.
As for exhaust Id go for just a cat back, I decatted mine and fitted vvc inlet and exhaust manifolds but im sure it just pulled more fuel through it. Used to pop lots and set of car alarms as I passed though
No vis issues or clutch issues like the KV6 which is a bonus. Although I dont think theres that much in the fuel. Maybe Ive just got a heavy foot but I could get 20-25mpg out of the 120!!
I dont believe the hg is a big risk Ive had 4 K-series based cars only one that had issues was the KV6 when I first got it.
