Have you tried experimenting with different reeds? I had an issue with milddle G and G# on my Cannonball Tenor - It liked to squeak or wobble. I was using Vandoren Java Reds - I switched to Daddario Jazz Selects and those reeds are actually longer & Wider. They fit the facing of my mouthpiece significantly better and I don't experience the issue nearly as much.
I also learned through practicing overtones how throat movement effects the pitch. I started relaxing and opening up my throat more whenever I play G & G#. Between the two, I don't have the squeaky issue any more! And I couldn't be happier
Practicing changing the opening of your throat - Think open and relaxed like when you yawn. That should help! Vice Versa, when you want to pop over tones or altissimo, think pulling your tongue back so you have half the airflow whilst keeping it towards the top of your mouth. Today I hit the 5th overtone on B and Bb! It's like when you whistle, you move your tongue forward or back to get different sounds. When you blow you open or close your throat, the more you close it the higher notes pop out. Love it
OP - Have you played both horns? Quality wise you don't have to worry - Both will last a long long time. Throw on a blindfold, have someone at the shop set up your mouthpiece and hand you a horn. Feel it, Play it, Record if you'd like. Let them know which one feels / sounds / plays the best and afterwards ask which horn it was! Just go with what YOU want. People will jump on Yani's who love Yani's, people will jump on Selmers who love Selmers. Don't listen to any of them, listen to your heart and play both