Not quite sure what you're trying to achieve, or where you're at really.

Firstly, the starter motor bolts to the engine...so that shouldn't change.

You do know that the LS bellhousing is pretty big ? I'm assuming your TVR bellhousing is much smaller. So do you have room ?
Likewise for the diameter of the GM clutch. The BH is big to accommodate this.

Slave cylinder you're on your own. The GM part for the LS engine is intended to bolt onto the T56 gearbox and is a concentric slave. This will not in any way go onto your T5.

Sounds like a lot of work swapping input shafts, when you could just buy a friction disc to suit ?

Back to the bellhousing. GM never made one to fit an LS engine for a T5 gearbox. So it will be an aftermarket part...so different brands could vary.

The older LT1 may have come with a T5 at some stage, and most of the BH holes will light up with an LS, so perhaps that may be an option.

Although again if you're using a UK T5, I think there are some clocking differences with a US T5. UK is clocked slightly towards the driver...and likewise for the US version. Opposite sides. Not a big thing though. Gearstick may just sit off slightly.
I think the bolt patterns for them are the same though...but not sure.

You're delving into a bit of a grey area.

I know your opinion on the box graig, but the amount of money that already went in the car (and the belief that the cts quaife is not that bad) considered I was thinking if a swap of bh, flywheel, clutch was also possible. Thanks for the companies name. I did not know them. Quicktime is also a brand and they make steel bh's. If the t5 would brake in the end, then this bh also takes the tko.....

Thanks for THE offer craig. I wil keep it mind. First thing to decide on (coming week) wil be what to do with the mbe ecu. Step by step.....

Coming monday i am ging to THE workshop to have a meet and decide what to do. THE situation as it is has to end woon.