I'm sure you'll get some great suggestions here, but before I can respond, I have a question. How does she prefer to be pleasured or finish while you're massaging her? You mention both a clitoral stimulator and an inserted toy - are you looking for something for penetration or just to use on her clit?

That's a very good question... multiple "endings" have worked very well. I used to spend a great amount of time giving her oral sex at the end of the massage, and after multiple orgasms, I would typically penetrate her... which (I think as a result of the extended oral sex) led to even more orgasms even without much thrusting involved. I then worked my way to the vibrating cock ring, and experimented with the other toys after that. It seems like the actual penetration is not necessary for orgasm, but as a submissive, there is something very appealing to me about using a penetrating toy on her instead of penetrating her myself. Therefore, I'd like to find a toy that had least had a penetration component to it.

If you've had success with the vibrating cock rings, bear in mind they can always be put on a simple slimline vibe which you may already have. If you don't, my personal favorite is this one: link. The traditional shaped vibrators come in so many sizes that there really is one out there for anyone, and they're generally affordable enough to keep trying until you find the right one. Problematically, they still might not stay in well.

You could also attempt a traditional vibrator with a little texture, anywhere from the Evolved Bliss to one of the shaped silicone Fun Factory toys (if you have a preference toward silicone). Also, if she prefers a more 'natural' feeling experience, a dildo that holds a bullet vibe like the Vibrating Champlette would probably work well, and you could again put a vibrating ring around any non-vibrating dildo. Unfortunately, these still will need to be thrusted or held in place.

Lastly, this may be a stretch coordination wise, but I've seen trickier things done with great results. They make harnesses that fit around the thigh that can also fit most other part of the body - arm, lower leg, etc. If there's a position you could massage her in with one of your legs attached to a harnessed vibrating or non-vibrating dildo, you could lightly thrust, allow her to move onto it, or just keep it in place (with or without a bullet and with or without a ring) and that would solve your problem about toys not staying in place. I'm not sure how this would fit into the submissive role you take on in the relationship since everyone's balance is different, but it might be worth a try if it sounds like something she'd like.

Hope this helps

I have not considered it... is a glass toy something most women are comfortable using if lubed properly? I guess when I started asking this question, I thought I would get recommendations for curved toys that allowed both g-spot and clitoral stimulation AND would stay in place during the massage. Or... some comments on the we vibe ii which seems like an ideal toy for this situation.

I appreciate all the out of the box thinking... please keep it coming.

My vaginal canal is very tight, I can't even take "regular" sized dildos comfortably, and I find that most glass toys work very well for me because they are so slick. If you do go that route, i'd recommend using a toy with some texture because I find that the straight untextured ones are difficult to keep in place.

Best of luck

it is my personal experience that glass actually requires no lube (for vaginal insertion) since it is so slick and does not absorb your body's natural lube. However, if you prefer to use lube anyway, it is compatible with anything. If there are any issues with comfort, it is usually that glass has no give and you have to be a little more gaurded in hard thrusting so as not to bruise the cervix... although that is also the case with most any type of solid toy you are inserting.
They come in so many shapes and textures your head will spin, lol.
For example, this is popular g-spotter... both ends are usable, creating two different sensations
link
And this one has textured nubs, but there are also ones with swirls, bulbs, and a variety of other textures from mild to extreme...
link

You should probably let her pick something out