This is timely as I’m considering doing something similar in our kitchen, though the island would have to be a lot smaller. Will be following along with interest.

If you're doing this with IKEA base cabinets you need to have a good number of casters to distribute the weight. At least 6 for the small size and 8 for the larger. I would also use double sided connectors to fasten the boxes together and screw a 1/2" or more sheet into the cabinets across the back for shear support . Use can fasten the finished panels from behind through that as well.

i did something similar 30 years ago. but, several of the casters were locking. be careful, as the island on wheels can get tippy. more short casters, not fewer higher.

@jdesign_gw, I am not sure what brand of cabinets we will use. I used the IKEA design tool since it's free....are the IKEA base cabinets much heavier than other brands/types?

Thanks for the detailed instructions :)

@Oliviag--I am thinking about what to store in the rolling island. Any dos and don'ts? Thanks!

I have designed many of these for people who want to be able to either enlarge their walking isles in the kitchen or in their living area depending on how many people are in the house at any given time. Everyone is always happy with it. Make sure you get locking wheels

The wheels you need are those intended for heavy duty toolboxes that you can get from the big box building supply sores and at least two of them need to be the kind you can flip a lever and lock the wheels so they don't turn and the cabinet will not move when you don't want it to.

Definitely not a pro but I managed to build a rolling cabinet that suits my needs -- the first carpenter project I tried. It turned out so well I wish I'd used oak boards instead of the least expensive I could find so it would look as good as it is useful. The first wheels I bought would not turn so the cabinet wouldn't roll because the cabinet and its mostly metal contents were too heavy. I replaced them with heavy duty tool box wheels and they work well.

I used fifteen individual plastic drawers about 5"x6"x16" and even the longest stainless steel soup ladles and spatulas and spoons, etc. fit in them well. I stacked the drawers in three rows of five and put wood vertically in between the rows and wrapped the cabinet w/oak plywood and trim boards. Don't know how or I'd post a pic.

Whether you choose a cabinet or just a table depends upon how you would use it and what you'd want/need to store beneath the countertop -- and whether you want to be able to roll it outside on the porch or deck or patio when entertaining..

You could find a table you like and add wheels to that.

https://www.google.com/search?q=large+rolling+table+island&source=lnms&tbm=isch&sa=X&ved=0ahUKEwjx4IKBtbvkAhWjV98KHWxUCGsQ_AUIEygC&biw=1344&bih=620#spf=1567746017829