Depends on your goal mate,
The B series turbo wont go past 450kw and to upgrade is roughly another 2k with fitment and tune.
A F6 short will handle 450rkw all day and be a fast car.
The costs ive had already puts me in 2 minds on that extra 100 or so kw and the extra cost it will take to reach it.
I started with a 7k sh*tta for work, now a 30 od k sh*tta and looking at a huge amount of coin to get my end goal of 550-600rkw.
The fighting with the misses about it is starting to lean me towards the cheapest option to get to my current turbos max out put.
Which is roughly 400-420rkw.