It has to be DESIGNED to integrate, as a whole look. Just doing ”something different” always looks like a mistake. Hire a kitchen designer. Islands have a hufe amount of requirements, from rkectrical to aidle space, to ventilation, etc. Don't get fixated on an pretty expensive structural alteration if the result will be pretty poor and non code compliant.

It depends. What color will the island be? What countertop will you use? I don't think you want an island that has no connection to the rest of the kitchen, so some of the elements should be repeated. Do you want the island as a focal point?

Google images, you will see a ton of examples of non”matching” islands. Yes, they do certainly work and can give your kitchen a lot of character. Old school designers go for the matchy or either the cabinets or countertop have to match. Thats not necessarily true today. You will however get many opinions, this is mine. good luck.

It depends on the total look you wish to achieve. As long as the combination is cohesive with your goals no problem. I wouldn’t put highly traditional island with slab peripheral cabinets so just use common sense.

What you’re describing gets done frequently on this site, and has been popular for 5+ years years. That said, my opinion is that it looks bad in all but the most expensive kitchens who used top of the line materials and designers. Ninety nine percent of the ones that get posted here look like two different kitchens mashed into the same room. Sort of like walking through the Big Box home improvement store kitchen design section, where you have a small display of Tuscan brown just a small aisle away from a grey modern section. point being that it can be done and look nice, but tread carefully.

We did slab front, inset cabs on our island and shaker on the perimeter. I really like it, but IMHO, it works because both have a traditional vibe. I'd post a pic, but it is not a high end kitchen and I have a thin skin ;-)

I'm more a fan of matching cabinets style but using a different color for the island.