is there an online supply for cabinets,dinettes,sofas,beds,pull down beds sinks etc? Like where do all the toybox and toyhauler guys purchase all their interior items besides the special cabinets they build themselves?

This is where I got mine
cabinets - IKEA (then modified the brackets)
bed - https://www.foambymail.com/BasicTwinMedium.html
shower pan and shower head/faucet - collins-n-co(574) 848-1118(ask for RV supplies)
furniture - either craigslist or https://www.discountvantruck.co...ries/rvfurniture.htm

call manufacturers direct. They're starving

Doc Weaver

Most of my stuff came from Jakesrvparts&salvage mostly surplus from manufacturers great prices also a place called ronthebusnut.com