Turbo on to GQ TB42E

Howdy, want some advice on best Turbo size/configuration to fit up to a 4.2EFI on gas and petrol. Not looking for max power increase, after more torgue than anything else. Extra 40 to 50kw/30 to 40% more power would be sufficient. Just want more ability to overtake,etc. Kinugawa are offering three options as per below. Seems the only difference between them is the size of compressor wheel.

1st option: 'TDO5H-16G'-
compressor wheel=48.3/68mm (EVO3-16G Wheel)
turbine wheel 49.2/56mm (TD05H/12 blade)
2nd option: 'TDO5H-18G'-
compressor wheel=50.3/68mm (EVO3-18G Wheel)
turbine wheel 49.2/56mm (TD05H/12 blade)
3rd option: 'TDO5H-16G'-
compressor wheel=52.5/68mm (EVO3-20G Wheel)
turbine wheel 49.2/56mm (TD05H/12 blade)

All three options above have the following:
compressor housing- A/R60, inlet 3", outlet 2"
turbine housing- 8cm/AR57 T3 inlet flange

Any info or advice much appreciated,

Cheers, Uncle Festa

For a petrol with an 8cm housing I would be using the 20g.

Hay mate. Jump over and stick up an intro for us. Just a little about yourself, sorta like a handshake. Something we ask of New members.
But as for turbos, newby is your man. Check out his builds in the members rides section.
Cheers