Here is another company for a few optional heights. Not cheap, but their products are quality made. I only have their Terrova adapter mount for the Mega 360 but it is quality built! https://www.cornfieldcrappiegear.com/shop?page=5
Tacklewarehouse had a clearance sell last month and I bought the Galilee Z-Force mount - raises the graph up 20" and it's very stout you can get them here http://buckbush.com/galilee-fishing-products.html
I got this one from tackle Warehouse very happy with it
Nice mount. I like the set up but how the heck do you step in your boat without tripping over it? Not just you. All these guys with so much electronics right where you need to get in the boat. I'd bust my arse!