if you want it to be kinky and to be used long distance, that would be something that you can use yourself.
One idea might be some kind of a remote-controlled vibrator for you. You can use lists like this:
Plus, you get an extra toy for yourself anyway
other - maybe a small flogger or something if you would be up to spanking yourself.
A collar - should be given to you by him, so you shouldn't try it I guess.
Another idea - you could buy "clone-a-willy" kit and get him to make a replica of his cock so that you can use it while playing. Note though that actually staying hard while staying still for 15 minutes while the form sets - can be a challenge. It also is very hard to do alone without help. And also those kits tend to make a huge mess, but if you two are up for some fun time (and definitely are up to see and touch each other naked) - then this may be for you. There are other avoidable potholes, so I recommend researching it and watching some tutorials, instead of just reading the short instruction and ending up with something unusable.
If I get any more ideas I'll let you know.