With a Ford V8 T5 box from an EB-EL going into a 240, the input shaft business need not be a nightmare.
Nightmares happen with 6-pot Ford boxes because the Aussie clusters don't mate to US-spec input shafts. People get the 6-pot boxes cheap, do the input shaft tooth count on these, note the bearing type, then order a US-type shaft to suit the adapter plates.... and then discover they don't fit because the helix angle is different on each.
That said, T5s are getting harder to find, and the asking prices are rising when they are found.
If W58s are getting unavailable, the next step may be the R154 Toyota box (IIRC @VolvoHordz did some research on this years ago, and I believe he looked at the Colorado box too). But AFAIK, adapter plates aren't available off the shelf for our cars.
The BNE Dynamics adapter plate also fits Tremec TKO boxes, as well as T5s.
Ready-made CD009 adapter plates are available for Volvos, but CD009 boxes aren't so easily found over here.
Rebuilding ODs in NSW? Diff Trans Spares did a T5 for me 30 years ago.... so, um, I'm a bit out of touch insofar as gear repair shops in NSW go. Harry's in Perth (TAS) is whom I'd go to over here, but that's no use to you unless you're doing Targa, heh.