Bottled Gas Cooker

We have a good but cheap bottle gas cooker, Picture here [You must be registered and logged in to see this link.]

The problem is that it has no real control, it is either off, low or high. This applies to both the rings and the oven. Has anyone any experience of or know where we might get a replacement that allows more control of the temperature. Ideally it should have a proper electric/piezo starter to save us using matches and getting burnt and some sort of thermostatic control of the oven. Our current one is perfectly servicable just lacks proper control. Of course it'll need to be the same size as the kitchen has been built around it but I think these things are a pretty standard size.

Any help appreciated.