The 2530s are no longer available so you need to find a second hand set, but the -5 is only a bees dick smaller and great results have been achieved with them especially when used with e85
The -9s are the same as the hks gt-ss turbos but cheaper due to not having hks written on the box
Basically if you want 400 go for the -5 and if a little under 350 is your goal go for the -9