I have seen similar ones work...I didn't have success with an incubator like that. By the time you have invested into the parts you could have just bought a cheap one that will work way better (like a Hova). Almost everyone I know including myself have had great success with a Hova. If you want something bigger get a Nature Spirit. I love mine and it holds amazing temps.
I agree, by the time you invest in all the parts you'd be better off with a normal incubator. They only run around $40 US (28 Euros) plus shipping.
I don't know where you can buy it abroad, but the hovabator incubator is available for sale at http://www.lllreptile.com. You might be able to get international shipping? I would look around, they're pretty common.