Looks like stock rb30 bracket and mount to me in that pic. Got a pic of the other side? other side should be shorter.
Engine x member should be a c210 one, well at least mine is.
Tail shaft yoke is the same size/spline, not 100% that lenght is the same, but i was told that it fits staight in, il measure mine up tomorrow to double check.
You can even reuse your L series gearbox, just need to slog out the top to bellhousing bolts, and modify the gear shifter because it will be on a angle due to the way the rb mounts up.
As for gearbox x member im not 100% as my coupe didnt come with one, but i was told a c210 one will fit the rb box.