Need help deciding on a finish

My wife wants me to build new cabinets on three walls of our sun/dining room. About 30 feet total. I asked her what she wanted them made of and got the “deer on the headlights” look. So, I made the mistake of telling her to go through my scrap bins, drums, and boxes and see if she could find anything she liked. Well after looking for almost an hour she brought a piece of waferboard that I’d run through the drum sander to see what it would look like for a craft project. It sands fairly smooth but the problem is all the depressions or voids between the pieces of wood that it’s made out of.

She really likes this stuff! The problems, as I see them is how do I fill the depressions/voids so the finish looks good. I don’t need a “piano” finish, but I would like a smooth finish I can be proud of. Also is there a stain that I can use to darken it slightly. I don’t know how well stain will work on this material with all the glue used in the manufacturing process.

I haven’t done much cabinetwork / furniturebuilding in a long time. I am very out of date on what’s available, and what’s best to use in this application.

Tomorrow I’m off to the lumberyard to get a sheet to cut up into tryout pieces to figure out how to make good looking cabinets (including raised panel doors and drawers) out of this stuff. Mainly I’m concerned on how to get a nice finish on it that will last. I figure that it will be treated no worse than a kitchen counter as far as spills and hot plates. There are also windows that sometimes get left open in the rain, so water resistance is a high priority.

I’m thinking a seal coat of 50/50 polyurethane & thinner, then second coat with 100% polyurethane. Do you think the 50/50 poly will self level enough to fill the depressions / voids. I’m open to any suggestions.

Thank you.