Z, I've had good luck on birch using powdered RIT dye mixed with denatured alcohol. I used a Preval sprayer to spray mine, but if you have your own airbrush it'll look even better. The dye does a much better job of coloring the wood than stain, as you found out stain can get blotchy on birch. As far as a finish is concerned, any of the wipe on oil finishes will do a good job. My favorite to date is Minwax Antique oil, it is harder and more durable than some of the other I've tried......Mike