Well what now... Gen1 to Gen ....?

I have my 2003 Gen 1 with a bad HV bat, I bought a core just to see if I could get some good modules out of it, it also had a burned voltage sense wire loom. I have both of them all charged up but now I need the sensor wire loom wiring diagram, I just need a picture of the plug for the voltage sensor wires (usually the ones that burn) which is what happened to mine. I was repairing it but it was so badly burned I don't have the pin out or diagram to tell me where the wires go in the plug..

ALSO:

Is converting to a gen 2 still the best option? I cant afford 1700$ for a new pack so please don't waste time telling me to just buy a new pack. I can get used HV bats for a bit of a discount I don't mind putting gen 2 into gen 1 housing but is this still the only option besides plug ins? All I see on this board about Gen 1 cars is super old and really not that helpfull when its from 2008.
Can you use a gen 3 or 4 or 5 or what ever in these cars? if so what's involved? Is this as simple as swapping out the modules? I'm not sure how this could be since they are different sizes. The local shop says they upgrade the computers when doing gen1 upgrades "becuase gen 1 is junk" in his words, but wont share the information because he knows me and knows I will just upgrade it myself, is anyone changing computers on these things?