Vehicles or towables to renovate

Looking for reliable vehicles/towables to use as a quality but cheap foundation for converting into a full time home on a lower budget.
Been researching cargo vans, military transport vehicles, step trucks, expedition vehicles, buses, etc. and am looking for any other unique types of vehicles (perhaps made for specialty purposes) that would be reliable enough as a foundation to support a conversion that I can work on.
Let me know if anyone has any experience or input