Axles last 15-20 years. You would replace the entire axle
(and get brakes!) not just the torsion bars (which are rubber). Cost $250-$700 depending on whether you have the axle
shipped, you do the welding, etc.
Yes, cabinets can be added, either by Scamp
, you can order from them, or build them yourself.
We have a powerful search engine here at FiberglassRV (upper right corner of window), I'd suggest clicking the "More Search Options" to search all forums (or select a particular form), place a four-character word in the "Search by Keywords" box and you're good to go. To search for multiple words place a plus sign ahead of the word. Click "Advance Usage Help" within the Search engine for more assistance.