I commented on those VitalMX Penton threads as I suspected it would be a KTM knockoff from Asia. Most people don't know that a lot of KTM accessories (and OEM KTM parts) are made in China. I hear the GPX is not so bad so if it is cheap, it could be something to look into.
As for AJP, my friend has had one for years. It's actually pretty nice and well made. CPD (Rieju importer) is now the importer for AJP so you can hit them up for parts.