First off, I have a Wenge Rosewood and two Wenge Ebony necks. One of the necks is on a fretless Warwick bass I have had since 96. I have never had it gum up with grime on me, and I tend to have sweaty hands. Wenge seems a lot like teflon, especially if you use the higher grit sandpapers on it to really get it smooth. Waxy, slick, porous, and easy to fly on. Just a note, Wenge and Rosewood look the same color, but the grain is much finer on the Rosewood. All of them are very versatile necks, with presence. They also seem like the wood has snap to it, weird observation, but it just has that nature.
The finish done by Warmoth is a steal. Very high quality, zero effort. If you add up all of the bits and pieces that you'd need to do it yourself (a Lacquer or Urethane version) you start to find it works out to be about equal. And that is not including your time. The vintage tint is quite yellow. You might want to look at a number of Ash body's raw, and they corresponding Yellow finish and Vintage Tint finishes to get an idea of the transformation. For Black Korina, the Tobacco burst also is always a favorite. I understand that you want the vintage look, but imagine it like this, you get a gradient of the colors you are after. I like the thin edge burst, and if I was doing it, I'd speak with a sales guy, and send an email with a picture of an example of what I wanted. Not exact, just in that sort of style.
Overall, I'd say you'll have a tough time going wrong with the project the way it is envisioned now. Have fun, keep us posted.
Patrick