5th injector and a cam would be your next steps, and def get that fuel mod done. (this is only make things safer no power)

also an 19 psi i'd look into water/methanol injection kit ( i have this)

but with that sort of power on them mods you must already have stuff that you dont know about (head or turbo etc etc)

my s2 makes 189bhp with the same mods as you (15psi instead of 19) and every tuner ive been to seems to think my engine has had work

when it was originally set up i was told it was standard and it would make between 160 and 170 and its making nearly 190 which suggests to me there is other stuff done i don't know about i'd think its the same with you car.

if u go fiesta efi now you'll lose power and it'll cost you to get it as you need the chip, injectors and a set up which is not cheap on EEC stuff