I might be missing a point (and I'm not an expert in electronic), but for a 130W Heatbed, you'll be running 230V@0.56A with a resistance of 400 ohms or 12V@10A with 1.1 ohms.

IMO, it's much more a problem to have 10A than 0.56A? You have much more current directly into the cicruit. Also, isnt the resistance the heatbed directly?

I will personally use this : http://www.aliexpress.com/item/Keeno...881899879.html (Custom order for my size if not available) with an SSR.