I don't know much about the OMS travel wing but I do know the Oxycheq is a really well built and reasonably priced wing.
My dealings with OMS have not been what I would expect from a company that talks a lot about customer service but my expereince with Oxycheq and its dealers was fantastic.
Another bonus with Oxycheq is that they will do mail order and you will still get the warrenty. I don't know if the other companies offer this service.
I did like the option of the shoulder dump but now that I've gotten used to not having it, I'm quite happy never to use a shoulder dump again. Besides, it's one less thing you have to maintain.
I do have an OMS wing for doubles and it has served me well over the years. But, I will probably not buy another since I LOVE my Oxycheq.
Either will probably work well, but take a look at some other companies before making your final decision. Who knows you might turn up something you like even better.