My condo has an 8' ceiling.

I am rebuilding my kitchen.

Galley, i.e. two separate parallel counters.

One side will have fluorescent undercounter lights under wall cabinets 30"h.

Over these I have built an 11"h 26"d header to project onto the counter.

This header is enclosed by walls / columns.

I'm thinking of 24V transformer halogen (or Xenon) lights there.

On the other side, there will be NO upper cabinets.

That side is open, not enclosed.

8' is my ceiling height there currently and I like it.

To light up that (sink) counter, what height drywall box is the best / smallest to contain overhead lights there?

What are the smallest size lights possible?

Am I better off hanging halogens off two suspended cables instead sinking them into a header box?

This is my first question in this forum. I'm mostly in kitchens, appliances and plumbing.