Have you looked into composite granite surfaces?
Dupont (makers of Corian) make a line called Zodiac- there is also a Canadian company that makes a line they call Hanstone. I work in construction (industrial) but we've been finding that the Hanstone is 1/3 of the cost of Zodiac for us and it is physically and chemically the same product.
I do mean really identical, they buy the rights to make a patented material from the same company but Dupont is known better so they charge more.
I don't know how concrete does as a top, I would be sure to ask how temperature sensitive it is, especially if you don't use A/C or set your thermostat low in the winter.