Go with Yamaha. Yamaha was my first oboe and then I had to send it in and the loner was a Selmer and it was so out of adjustment that I couldn't even play on it. My Yamaha got me throught my fist audition. I have never played on a jupiter oboe but a friend of mine plays bass clarinet and Contra alto clarinet and she used to play on a Jupiter and she hated the key work. I also think that jupiter is mainly a flute maker but I don't know for sure.
Yamaha is a great brand. I'd go with one of those. I'm not a true oboe player, so I can't give you much more information. Selmer is all right (at least their saxophones are), Jupiter is more of a beginners instrument. They're getting better, though. They used to create really cheap instruments. They create more than just flutes.
Not all Selmer instruments are "crap". Selmer Paris makes amazing instruments, and more than saxophones. Selmer USA instrument's aren't as good as Paris, but they're still decent beginner/intermediate instruments.
More on Jupiter. I've only played on one Jupiter instrument. It was a tenor sax, a few times for pep band. This horn was very nice to play. It was really smooth and responsive. I think it almost played better than the tenors I played in quartet, which were Yamahas.