Serge wrote:

Thanks Brian for good info.

They are also called Topdeck (www.peakuk and www.palm-equipment.co.uk).
Most of them look too heavy for what I wanted to use it for.

I am looking for open cockpit kayak like WSB and was thinking about
using combo.
I do not know if it is a good idea, but weather where I live
is almost the same year around so it is not like I have to change
between summer and winter gear much and could use jacket-skirt with
layers if needed.

Given that, why would you bother with a one-piece system at all? A spray
skirt and a jacket would be more versatile and probably less expensive.