Sounds like you have lots of good advice. I do think that trying a papsan chair or a swing might be the best option to try first, especially since she is already in her own room. If you can keep her there and help her to sleep well, that will help everyone and get sleep for everyone. My sister used her stroller for my nephew - that kept him elevated, yet he felt comfortable and snuggled.
If sleep and missing your husband are a large part of the problem, having her sleep in a swing or bouncer or elevated crib mattress should help the reflux and give you and your husband your bed back - together.
It doesn't sound like co-sleeping is actually going to help her sleep better, but be easier on you, which in the long run, won't help anything, especially when you want her to sleep because she feels better. Also, not be make anyone upset, but there are usually a lot of posts regarding how difficult it is to stop co-sleeping because the transition is difficult and takes up a lot of sleep time. Just something to think about.
Whatever solution you choose, it should address the acid reflux, not just your sleep and hers.