Ecu Wiring For 1JZ Into Is200?

[NickC]

Hey guys, I've got a 1999 is200

was auto from shop, currently old engine and box is out and the loom along with it, (ecu and that part of the wiring is still in the car)

I've got a 1jz vvti box and everything needed for the swap besides an ecu, (bunch of goodies to go on as well so it wont be stock, aiming for 350-450hpish)

I'm planning for a haltech 750, but I'm just not sure on the wiring side of things, is my best bet just a full custom loom? or is there a more cost effective way,

i.e. looking on golebys, there's a;

1. plug and pin set       

2. basic universal wire-in harness kit       

3. premium universal wire-in harness kit       

not sure if this is the right spot to ask (sorry if its wrong) but just trying to see if i can get some advice for it as im not 100% on what to do, not the greatest at the electrical/loom side of things. 

but yeah basically just wanna know if buying one of those would work / make the custom loom cheaper/simpler, or if its pointless and just buy the ecu and go from there.