A $1400 budget is going to be rather tough. You might get a horn for that but it will probably need work.
Of those two you mentioned, the Buescher will probably be a better horn. I'm assuming they're both '60s-era? Bueschers from that time period weren't as well set up when new as the pre-buyout horns had been, but when properly overhauled they are still decent instruments. Conns just plain went downhill after about 1960, and by the '70s they were just making crap.
Ergonomics of vintage American horns are strange compared to modern horns, but you get used to it. I personally find Buescher's ergos much more comfortable than Conn, but my True Tone requires fairly large hands and/or long fingers.
Intonation isn't as good as a modern horn, but you're welcome to spend 2.5x your budget to correct that. IME Bueschers are a little better than Conns, with the 400 being in the 'not too bad' category. Use a mouthpiece that agrees with them and either will be fine - a Link will work on either as a starting point.
There's also preference. Vintage American baris have way more guts and depth of tone than most modern horns. I personally love this about them, but a lot of people, particularly Selmer and Yanagisawa fans, seem to have a hard time controlling them at least at first. If you're used to German horns IME you'll probably be able to mostly handle one.
There are also the tone and feel differences between the options; I reliably like Buescher saxes, I liked the one King bari I tried, I had a blast on the Martin I tried although I wouldn't want to own one, and I have yet to play a Conn I like. None of that means anything toward your taste, but if you can try the instruments first it is 100% worth doing so.