So, I currently have two sierra, neither is running

I want to get my first one done up and back on the road before I start messing with my new one that I bought a few weeks ago off another member on this board (95 gti sierra)
The first ones engine was well and truly had it, so I pulled it out considering doing a rebuild. But at the end on the day I kind of couldn't really be bothered.... and of course I don't really want to take the chance of fucking it up not knowing what I am doing. So I've been looking around for a 1.3L engine to put in but haven't found much.
I ran across this add on ebay
http://www.ebay.com/itm/330681297530?ss ... 1423.l2649 (it has already been listed in the ebay thread)
Really tempted to go this route, it is a lot more than I had planned to spend, but at least it will be done.
I've seen a similar set up with high km's go for around $1500 on here not too long ago, is it really worth it for such an engine? I know a lot of time and money goes into the conversion, would just like to get some opinions?
Also, most of the threads I have read involve attaching the g16b to the standard sierra gearbox and transfer (pls correct me if I have that wrong), this one has a vitara gearbox and transfer, what would that mean as far as gearing goes? would it be different?
This might be a very stupid question (I have almost no experience with these efi engines), can I just plug in the computer and wires and go? will the computer need to be tuned or will it already be tuned for the engine (I assume it is the standard ecu)? I would hate to have to muck around with it like I will need to with my GTI

I guess my only other question is what else would I need to complete the conversion? I know some people have said they get overheating issues with the standard sierra radiator others don't. Any other bits I would need to consider? what kind of exhaust do these engines have standard, I guess my brand new set of 1.3L 2" extractors will be no good to me

Also, any other questions I should be asking him?
Sorry about this thread being so long,
I would really really appreciate any info you guys could give me

Cheers