At this point I am not sure what "support" Bigfoot would offer anyway. Appliances are readily available as needed and structurally ,regular maintenance and repairs should take care of that.
Find a good Mobile RV mechanic vs brick and mortar and get the help you may need.
If it were me ( I repair my own stuff) I would go for it. Duramax is great, leave it stock. It goes fast enough and is strong enough.
When I read online about my Duramax the one's complaining have them chipped or performance mod. Also learn the proper maintenance of the diesel. Fuel filters, how to change, how to prime.
I use a fuel conditioner also. Diesel fuel has lost it "lubricity" I use Optilube XPD. Lucas is top line also.