I just got a piece of surplus ½" thick composit material, cut it to size on the table saw, routed a finished edge and glued it down. The composit cost me $10 at a lumber outlet that deals in "odd" material. I'm sure just about any local countertop manufacturer has plenty they will sell cheap. The only thing with composit is it's not heat proof (I.e. You can't put a hot pan directly from the stove to it).
Stainless is another good, but expensive option and would require something under it.
Thanks - actually I hate the sink, myself! It seemed like a great idea ($100 or so from HD online) but after using it I realized a SS one would not only have been cheaper but larger and deeper and you could put hot pans in it to boot. Everything in life (and vans) is compromise in the end.
We used a material like Formica from H-D for the galley and dinette top. I have enough left over to do a couple of other vans! Look at IKEA for sink. We made this one fit and the stainless drainboard is great to put the butane stove top on. http://www.ikea.com/us/en/catalog/products/S39158184/
RD, could you please check the dimensions of that sink. Ikea just gives the lingth and width. I am curious as to how deep the sink bowl is. Also, it appears but does not state that it comes with the drain hardware and stopper. Does it come with those?
I'm assuming it doesn't come with the drain hardware and stopper. Maybe Ikea does things differently but normally don't come with that.
For counter tops, as RD suggested, is the option I'd use if I didn't use wood. There is a discount building supply here that sells it dirt cheap in tons of different colors. Color choice has really improved over the last 10 years. Now there are lots that look close enough to granite/marble etc. It is dirt cheap too. Granite look alikes are about $10-11 a linear foot.
The sink did come with drain and basket stopper. The dimensions are 27 1/2 X 19 5/8 X 5 3/4 and the cut out opening must be 26 1/2 X 18 5/8. The total depth total with a trap on it was 10”+-
See drain [ame]https://www.amazon.com/Camco-37420-Flexible-Camper-Drain/dp/B000EDUTPO/ref=sr_1_1?ie=UTF8&qid=1504561927&sr=8-1&keywords=camco+sink+drain[/ame]