Ebony* will do custom cameras but this is an expensive route to take. You would probably find it cheaper to buy a higher spec camera . I have just bought the 45SU (after waiting almost 6 months for it to be made & delivered from Japan to England). The standard model is in Ebony but they will make it in the lighter weight mahogony wood if you prefer.
You can discuss your requirements and prices by emailing Hiromi directly. ( email@example.com ). I think the 45SU might be too heavy for you weighing in at 2.6 Kg. You could go for the cheaper 45S model but that does not offer assymetrical focussing and the bellows are not interchangable. With the 45SU you can use a 58mm Schneider XL lens without any movements with the standard universal bellows or with some movements using the bag bellows. Ebony do offer the option of non-folding field cameras which are easier & quicker to set up, and you can leave the lens mounted. Ebony are so expensive because the whole camera and parts (including even the screws) are handmade! The best quality titanium & Ebony are very hard to work, so the labour costs are much higher. That said, they are VERY sturdy, "Matelot-Proof" cameras!
If you are interested you can get them from Bruce's Field Camera Store, via ebay, link below.
*Ebony cameras: http://www.ebonycamera.com/cam.html