Engine code differences

Hi, looking to do the 1.8 turbo  conversion and have read through the conversion post, just a quick question engine codes ? Aum aux bam agu etc eTc Read a few different websites and can see most of it is about the turbo and bhp, The conversion guide says to use a agu engine what differences does it make using a different coded turbo ? The last thing I want is to make it harder for myself in the long run cheers in advance 
Kris 

I think the agu is probably easiest, for instance i think they come with a cable throttle body, so saves having to fit a dbw throttle pedal and associated wiring..and maybe more easier parts.

Thanks, I did read that also, after more reading I think that is the best way to go, so thanks for taking the time to reply 
Kris 

http://www.clubvw.org.au/vwengines

So I've stolen a engine! Aum 180
please need help😩😩, I know I'll need to change the throttle pedal as it not cable but this is a 6 speed 1.8 t so what does that do for the gearbox what do I need to guys please help! Thanks in advance 

throttle pedal is easy to make a bracket for, in fact I think crazyquiff does one along with hydro conversion kit?

bin the 6 speed box and go 5 speed 02a/j its a lot of hassle and expense to go 6 speed

Thanks mate 👍🏻