Thanks for the replies and advice guys.
Andy. You have me confused for someone who knows what he's doing!!! Design it myself!??? Indeed! LOL

I will contact Active tech as you suggest. Thanks for that. BTW how's the ole Air con working? Well I hope!
Mike. I will also have a word with ARE. Thanks for the link.
What a great site and community this is! (Thanks Ron)
More info into my predicament, just incase you're interested, I'd welcome input.........
I fancy the ZFQ. Ratios are great, Chris Melia is helpful and the product has received rave reviews and some impressive track results to boot.
The ZFQ drive flange to front of box dimension is small at 5.6". I have under ten inches of space available if I hope to avoid silly drive shaft angles. Chris can supply a bell housing that is 4" deep and then I need an adapter. This would run me to just about the max of 10 inches. Therefore, I hope to get a custom bell to come in at under or at least no greater than 4" deep, to win back a more optimum angle on the shafts.
Is it realistic to expect to fit a clutch and release mechanism into a space only 4" deep, (to give me a total measurement of 9 1/2")? The flyheel is partially recessed into the block, leaving just 1cm within the bell area.
I'd appreciate your thoughts as I know nuffin!