Hi
I'm late to join this thread, so apologies if you've already completed your build! A few years ago in the uk I did a course in decorative paint effects... Faux woodgrain, stencilling etc. As others have said, a pale base coat, then a tinted semi transparent finish over that (we used to use scumble glaze) but an oil based varnish would probably be ok. I wouldn't use acrylic (water based) as it might dry too fast, before you've created all your grain patterns.
One way of adding a very subtle woodgrain is a technique called dragging. You can buy a special dragging brush, or get similar effects with any long bristle decorating brush, and you drag it through your glaze or varnish with long even strokes right down the full length. Heres the type of effect it creates
For a stronger effect you need a Graining rocker. Made of rubber etc, has a curved surface, and woodgrain texture embossed into it. By dragging it along your glaze or varnish, whilst also rocking it gently back and forth, you get a quite realistic grain.
GOOD LUCK, WHATEVER YOU DECIDE