I've been researching the same thing. Had the whole set up years ago with full porsche 944 n/a and knew it could be done on stock/dropped drum spindles. Just never got round to it and sold the bits (luckily not the wheels).
I've just bought the full 944 n/a legs again; hubs, discs and calipers. However it looks like dropped drum spindles are extinct. A lot of links on Google but not finding them.
Some of the same players mentioned; Transporthaus, vdubengineering, wagon west etc but hard to find out if still operating. Transport has at C&C but don't seem to have stock, Alex doesn't seem to be about anymore.
So what are the options now? I do have two sets of 20mm 5x112 to 5x130 adapters that were a back up but would rather do the swap as this limits width one standard front beam.
I'm on earlybay transporterhaus dropped spindles running standard discs/calipers. Got 944 hubs/discs, so need the spacer kit as above and calipers brackets. 944 n/a calipers were able to be used on drum spindles, but for disc spindles iirc it was 944 turbo or wilwood. Boxter and 911 also get mentioned. Just trying to get a clear Steering (no pun intended)
I'm OK on the back as still got the porsche drilled transporterhaus drums/hubs/stub axles I bought years ago.
Thank you for any advice, believe me I've read through many threads on here (even my own from June 2011) , late bay, the samba but seem to be going in circles