Which propshaft? (M50B25 gearbox)

[flashBE]

I'm trying to figure out "the best bang for the buck" arrangement but I keep reading different things.

My question is: Which proshaft will fit behind an M50B25 gearbox with small (78mm) flange?
I've read that the e30 320i and 325i propshafts will do he trick because the e30 gearboxes also use the 78mm flange, but I'm wondering if they're suitable lengthwise?

Does the length even matter? The 320i one is 1526mm and the 325i one 1489mm.

Thanks

[BATTS91]

E36 front half of the prop with E30 centre bearing will do the trick ;)

There was a good guide stickyed but i believe its got lost in the process of going over the the wiki guide .

[flashBE]

Thanks, but I decided to go with the M40 gearbox, 320i gearbox links, Z3M shortshifter, 320i prop and 168mm 4.45 diff. I have all those parts lying around so it can be done low budget.
Also using the 6.3kg flywheel and starter from an '84 M20 btw. Can be fitted without any grinding.