I've read about Protection and Performance (http://www.ppcages.com/
) in the UK and from what little I've read they might be a reasonable alternative to SD.
Check out their ebay shop. Their (front only) external rack 110 rack (not NAS 110) is about $850 at today's exchange rate; then throw shipping on top. It might be a good start though and you could get someone to fab the rest internally down the road.
If you use this set up you'd need to have them (or someone local to you) fab up the rest based on something similar to the D90 SW:
I'd be curious to see what they would quote for a full 110 cage.
Oh and here's the external they have for a 110 Double cab:
That gets you part way there to a NAS 110 at around $2,700+ mods/fab to replicate NAS.