I would use an
oil based exterion poly for your
project. First it needs to be sanded (220 grit) well, then put on two coats. Poly takes awhile to dry so plan on letting it sit and dry for several days before using OOOO (four outt) stealwool and two more coats. Let it dry again then lightly with OOOO and wax it with paste wax.
That is what I do on the furniture I build and get great results. Good Luck