boost increase
 

what sort of boost incease do you get from tek 3 sports cat , induction, 255 fuel pump and fmic UK00 uk turbo

Boost with a tec3 is set to make the engine perform at its best,but within certain limits.
The mapper will determin how much boost is possible and how it develops to some degree.
The Mods you have may allow more boost to be used if the car is running healthy.
I think you are asking how much power will you have.
I am not an expert suggest you speak to an expert such as Powerstation or similar tuning company

MY UK MY99 Turbo runs 16/17psi on a tek 2 with decat.