At a minimum, I’d want a good steel or wrought iron bed with a headboard & footboard. You can usually leave the chains attached and stuff them between the mattress & box-spring so you can be chained down quickly..

Massage tables are another option, most fold up and stuff into a bag, & they’re usually narrow enough so your Dom can work both sides.. with enough rope, you can be made completely immobile, while still being fairly comfortable.. And they can be easily explained if Mom comes to visit & notices it.. The best part is the price, check Craigslist and you’ll often find really nice ones for under $100..