White quartz with very minimal gray veining, a white element would be a great addition.

Thank you for your reply... you think it’s ok to mix quartz and granite?

Don’t think I’d mix vaining with vaining. Either do a simple plain tip from a lift color on the current countertops. Or technically you can go with darker colors from the countertops. Which I think I’d avoid. But your call. Do you want to see light or dark?

I definitely Would prefer to lighten up the space. What material are you suggesting?

I think it's better to mix quartz and granite than to try to mix granite and granite. Your granite has a lot going on, so the second counter material...can't. It needs to be as close to a solid as you can get. There are very few granites that fit the bill, and all the ones I know of are black. Quartzes have solid or near-solid colors in lighter shades. I would not do a faux marble look, but something solid (like Silestone White Zeus Extreme) or minimally speckled (one that looks solid from a distance). Or you could do Corian in a solid that works with the perimeter.

Does anyone think I should just try to find another slab of same granite (blanc du blanc) to match?

I think you may have a hard time finding a similar looking slab, based on the time gap. They would now be mining from a different location and the slabs might not look that much alike. If you’re okay with that variation, the same granite could work. I think something light, a solid quartz, is also a good idea.

If you can find the same granite, and the appearance is close enough to what you have, then yeah, definitely that could work. I was only cautioning against the perils of trying to coordinate two different granites. But Muriel is right, there can be a lot of variation within the same type of granite, so even with the same name it might not be a good match. But it's certainly worth looking.

If you could find the granite to match, that would be my first pick. However, since that is maybe unlikely, I would pick a color from your existing color, and find a slab in that color, that is solid color, and use that.

The solid light quartz would work, but since it's not large enough for stools, you should be able to keep the butcher block, which I would stain darker to match the cabinets.

Sand the countertop as planned. Paint the island when the boys aren't quite so little. :)

I think it's fine. what I would advise you to spend your money on is professional lighting. canned lights. that will make all the difference in there.

you busy flooring, the other stone, the tile, the cabinets, now you want to add another color to the mix? I think it would be too much. the butcher block is fine for now. (or, see if you can pick up another piece of Alaska White to match your other)

save up the money (except do the lighting) until the boys get a little older, (although to be clear, mine is 25 and is still a mess around my cabinets. he doesn't bang toys on them, but he's a tornado when he's cooking) and maybe you can reface them or get new ones.