I may have a few suggestions.
Well there is already floggers, whips, cuffs and chains, what else could you possibly want??
Before moving into a larger house for the three of us, we had a guest room with a normal bed. We bought restraints that hid under the mattress sold in sex stores. Out of sight until needed. We hung a hanging lamp from a hook in the ceiling which was used to attach other things to when we played. Our closet had a smaller locked closet inside it to hold our play gear.