Newbie with a pipedream for an E30, advice / opinions on engine swap plzz

[delusion 1]

Hey team, just got an auto 1991 E30 318i from a friend who upgraded and wanted it gone so I got it for pretty much wreckers rates, couldn't pass it up!

The pipedream / plan is to manual convert it with a m52b28 or m50b25 -  Not planning on building a drift hack or track car, just a cool car with more legs than the 1.8 offers

Hoping I'll be able to pick the brains of some more clued up E30 owners and anyone who has done auto / manual conversions and /or m50/2 swaps...

 

I've found a bunch of resources online with relatively vague information, but no well documented builds with parts / process listed coherently

Specific things I'm not sure on for either engine would be;

Transmission // From the donor the engine came with?

Diff // Donor again - ratios?

Driveshaft // E30, donor car or custom?

ECU / Electrical // Got super confused reading about OBD1/2 - what's the process that still allows the bells and whistles of the E30 lights, gauges, elec windows etc -- I know nothing about auto electronics so this will likely done by an auto sparky

 

If anyone could shoot me some links they used / found helpful, or better yet flick me a copy of the E30 M50/2 Swap bible that I can follow to a T that'd be awesome!

 

Thanks in advance