1906 and 1908 Navies were issued with a stock, Type 1 holster and pouch, and came in both black and brown leather, although most of the brown ones were dyed black pursuant to an order dated 1916. 1916/17 Navies were mostly (but not always) issued without a stock and with Type 2 leather. They too came in both black and brown but most of the ones I've seen have been brown, admittedly a small statistical sample.
Anyway, since you are getting a stock I think you should choose Type 1, either black or brown.
Enclosed are photos of a Type 1, a Type 1 converted to Type 2, and a Type 2.
NH 1, 3 & 5.jpgNH 1, 3 & 5 (1).jpg