I have an older style TKO, but fitting is the same. Go the TKO's
What are you doing for a bellhousing?
1. Mal Wood machines your new input shaft down to use a normal toploader bellhousing? ($150 minus labour to strip it down, may be included in your price?)
2. Custom alloy one made by Dellows automotive ($450)
3. Spacer plate $250 (more unwanted flex).
Mal recommends option #1.
The TKO's normally come with a shifter!! Make sure you're not getting double tapped!
New throwout bearing $45
You'll need a beefed up metallic style clutch disc and matching pressure plate otherwise you'll fry a heavy duty organic on the first launch. Which one do you have in mind?
When I was in Perth I dealt with the Tremec dealers in Welshpool, can't remember their name but I can get it if you like.
Tremec speedo cog. DON'T use toploader or auto ones. Your speedo sender will fit in OK, just with a new cog from Mal etc.
They're a BIG box and you may have clearance issues in the trans tunnel. Nothing some tin snips won't fix and then screw on a sheet of stainless steel etc of weld it in.
The "feet" on the extension housing sit 20mm higher on the TKO (where if sits on the crossmember). This allows the back of the gearbox to sit lower making more room in the trans tunnel, but it can also screw your driveline front uni angles up as the driveshaft has to kick up to the diff. All depends on how much your coupe has been lowered. CHECK it before giving it a boot otherwise you can get some bad vibrations. You can fix it using spacers under the crossmember mount. My XD has been lowered about 2" which hurt me a little.
Billet Flywheel and ARP bolts (assume you already have for toploader).
ps: nugget378 just destroyed his TKO600!!! Not a box problem, but it got stripped down for an inspection and the mechanic refitted some parts wrong!! Destroyed a heap of gears etc and about $2000 to fix! ONLY use professional guys who know the boxes.
Mal is great for customer service and follow-up warranty.