We ordered this harness to try. Although it's shown with a female wearing it, I think it would work perfectly for a husband wearing a cage.
Similar here for both of us.... Mistress/Wife for pegging ...me for her needs because I am caged, and no where near what the size she likes to experience.
The harness looks good, it's similar to the one my Mistress uses on me, I'm not allowed to use it, it's for her to peg me only, but it does fit me and would do the job on her. Does it have fittings to take bigger dildos?
It has 3 different rings for attaching flared base dildos. We also ordered several of those, including one that vibrates. This is from extremerestraints.com.