http://www.westmarine.com/buy/sikken...04_128_002_501
this is a link to it, probably find it cheaper somewhere else. you need to get a qt of the finish you want and a qt of the overcoat. i use the gloss. it seems "harder" and holds up better. usually sometime in the spring WM will run a sale with it half price.
not trying to talk you out of varnish, might want to get up with inaforty and see what is involved. the one time i used it, it needed to be redone in a year.