Are you trying to heat the room or take the cool off of the time. Electric strips won't heat the room.

Not raising the height of the floor seems to indicate that you may not be planning to insulate the floor from the slab, in which case you may loose a lot of heat to the slab and ground below. I would rethink this aspect of the project if this were so.

In a small area it may be more economical to install electric radiant as opposed to hydronic. Keep in mind that with electric radiant you may be exposing yourself and family to higher levels of (non-ionizing) electro-magnetic radiation (EMR). Try to choose a product that is constructed and wired in such a way that either cancels out or attenuates this effect.

SR

Here is a link that might be useful: Electric radiant floor heating without electromagnetic radiation!

Since the electric cables will probably be in contact with the slab, and since the slab is probably thermal-bridged to the outdoors or to mother earth, I'll agree that it might not be a suitable solution in this case.

In this case, consider putting cables under a 2cm quartz countertop and the 2cm quartz side panel at the end of the countertop run. The goal here is to keep it warm, generating constant heat, radiating constantly. Not so hot that it would melt butter.

But, there is still a lot of information unknown, unwritten, unexpressed so far. It may be possible to heat a thin ceramic tile (e.g. Kerlite) and to install a thin membrane between the slab and the heating cables. Post again.

It IS possible to get sufficient heat from electric cables to heat the kitchen entirely. There are many reasons for this. It is a lot of work to write it all out, and later to refute the naysayers who find it hard to believe, so I will abstain from this work at this time.