Just looking at the specs of the 3020 and your Proxxon the 3020 has a 200W spindle and your Proxxon is a 100W spindle so you'd be downgrading power...probably upgrading quality mind ;)

Why don't you make your own spindle? I have (not used it as not built my machine yet!) so it must be fairly easy lol there are a few threads on here to guide you?