Hello, have a question regarding kitchen sink plumbing. If I leave as is, its a classic S trap. I'd also like to add an air admittance valve. Any suggestions?

I was thinking of maybe cutting the PVC off low and then have it 90 towards to back right corner of the cabinet before bending it back upwards. Therefore, I could get the PVC a little bit further away from the center of the sink so I can extend the trap arm length. Does that sound OK? And if so, where should I add the AAV? Do I add it along the trap arm or above and in line with the PVC? I've seen people do it both ways.

Thanks!