There are many many more Dometic/SMEV/Cramer cooktops available in Europe for example (
Mobile Kitchen | Product Categories | Dometic United Kingdom). Just bear in mind a cooktop is called a hob in Europe. Panther carry a few here, but also remember they supply the marine market.
I imported mine to get the option (cooktop and sink combo) I wanted (and a matching countersunk waste bin).
I also imported a match faucet as an alternative to the rubbish design version used in the Interstates!
Check out
Reimo in Germany (they have agents in the US and ship for you), or
Jacksons Leisure Supplies UK in the UK who ship with Fedex.