You will give up 50 inches of base cabinet storage to install the U. You will get back 50" at the bottom of the U. So that part is a wash.

If you then install corner lazy susans, you will get back about 32", but lazy susans are very inconvenient storage, to be avoided if possible.

You would probably be better off sticking with a well-designed galley kitchen.

But, what you should look into are deeper than normal cabinets. You should be able to extend the cabinets on one side to about 30" and still have the minimum walk space between the cabinets, which would increase your storage (and your countertop space, 25%.

Follow the link to a resource that may help you with your kitchen design.

Here is a link that might be useful: Small Kitchen Design

Brooklyngalley's kitchen is the smartest use of small space I've ever seen.

http://ths.gardenweb.com/forums/load/kitchbath/msg0516324013092.html