Hi benifur
No you have not made a mistake. I have had mine for about 7 months now and it still runs great. There will be no problem finding parts, here's a link to a great hobby shop [link]http://www.offshoreelectrics.com/[/link] . New era also have some parts.
You should buy a new steering servo the stock one is to weak, also check if you have the latest version of the gen. It should have black spur and Pinion gears.
But you should check www.cengenesis.com
You will find all about the gen.
So good luck with your truck