I am also in a country where there is very little technical support. You quickly learn how to do your own PM which reduces any chance of your roaster needing serious work. My suggestion is you explain your needs to which ever company you decide to buy a roaster from. Generally the people on the other end of the phone/or the email are more than happy to help troubleshoot
I have used Ambex in the past...never had a problem...just kept it lubed...need a grease gun...$16.00..I think there are a total of 3 or 4 fittings to be greased..Other than that keep the chaff collectors clean and you are good to go!