Not much homework to do.
Get output shaft to match 241.
Get lokar cable shift.
Get tci 4l80E control box.
That controller makes the most sense since you already have the EZ-EFI 2.0. Having two TPS wouldn't make any sense.
And the 4L80E is not much different in length than the 700R4 total length, but I am not sure about the difference without the tailhousing. If I get time I could measure mine, I have a 80 in the regal and a 60 in the trailblazer. But I think it will depend on teh adaptor anyway, and I don't have one of those for an 80.
As for the adaptor, I think it is different in the 700, because it has the 4 bolt pattern like the TH350 I think. But I think some of the newer ones like the 4L65E may have the same 6 bolt pattern as the 80, but I am not 100% sure on that one.