If you're just trying out the oboe as a beginner then the best oboe you can get is a sudent model with out all the uneeded trill keys and the 3rd octave key or low Bb key ect....student models like Artley 18Q, Artley 19Q and Buffet Crampon BC4012-2-0 are the way to go.
but if you want to start on an Intermediate model, which saves you having to buy a begginer and then eventually an Intermediate the best you could get would be probably a Buffet Crampon BC4052-2-0 which has the extra 3rd octive key that allows easier playing and a low Bb key that expands your range of playing
advanced oboes are pretty complicated and are only usually bought when you are sure that oboe is for you.
As for the tuning eg 440/441/443Hz ummmmmm.........I'm not to sure if it matters much because i have never heard of them.
Here is a list of beginner oboes:
Yamaha Oboe YOB-441P
Yamaha Oboe YOB-241
Yamaha Student Oboe YOB-211
Yamaha Oboe YOB-831
Buffet Crampon BC4012-2-0
Artley 18Q...just to name a few
P.S If your looking a an oboe and aren't sure if it has a low Bb key just look at the bell, if it has keys on the bell then it has a low Bb and if it dosen't it should have two holes which you cover with your knees to make the note.
but most oboe music hardly ever goes that low. The only thing is that it sometimes does go that low and when it does it's easier to just press a key instead of having to cover the hole with your knees. Not to mention that when you stand up and play it is impossible to cover the towo holes with your knees.
anyway, most begginer oboe music never goes that low only intermediate and advance do so......
Yamaha Oboe YOB-441A
Yamaha YOB441 Series Oboes Grenadilla Wood Body
Buffet Crampon BC4052-2-0
Selmer Intermediate Oboe 121
Buffet Performance Oboe BC4052-2-0
Fox Model 330 Intermediate Oboe
Selmer Intermediate Oboe 104B
Jupiter Intermediate Deluxe Oboe 355
and so on......
i won't include advanced models because alomost no one starts on them.
by the way most pro oboe players almost always play their double intrument the english horn or cor anglais, just so you know.
overall almost every obe gives the same sound, he extra keys are just for ease and alternative fingerings.
I started on a yamaha YOB-241 because that was the only oboe the school had.
If i was you i would go for a begginer oboe because they don't cost as much and you don't need the extra keys right away.
If you want an extra challenge and not have to buy a begginer and intermediate go for an intermediate with the extra low Bb key for ease and comfort. And as i said most begginer oboe music dosen't include the low Bb so it's useless until you are an intermediate player.
Honestly, it doesn't matter which kind you buy. A good oboe player can get out all the notes they need even from a bare bones student oboe (like myself). Just hug it with your knees for the low Bb, and pinch your reed real tight for high G, A, etc.