a good clear wood finish?

I'd suggest shellac... it's easily repaired and can be deglossed.

Shellac is about the only thing that will prevent knot resins from bleeding through. Though it is shiny, you can do one of two things:

1) Knock down the gloss after several coats by rubbing with steel wool and furniture wax. Buff the wax with a soft cloth.

2) Apply a top coat or two of satin varnish. If you are using a polyurethane varnish, be sure your shellac is de-waxed. Zinnser's Seal Coat is a good choice.

Helmsman and Verathane both have wood protector varnish in Matte finishes. I just bought some of each, and while it's not as matte as some paints can be, it's definitely not as shiny as regular varnish!!

Finishes are pretty good these days. I've gone with Helmsman clear satin and had very good luck with it. Would recommend putting on a very light wood stain before that though.

Satin urethane, which is not shiny but matte.