Depends in part where you live. Avios can be a great program for short flights, especially from an AA hub. WN is probably your best bet if you have someone to serve as Companion and can acquire the points.

110K is a lot of points by December if you don't fly much and only spend $3K a month. Going to be very hard to get there. Might need to aim for $4500-5000 minimum and even then you'll need more from other sources. Start looking for additional ways to get points. Pay bills for your parents/siblings/business and get reimbursed, that sort of thing. Put everything on the CC.

Remember if you use the WN Visa to buy WN tickets, you get double RR points. So it's 8 per dollar all-in rather than the 6 that you get for the flight itself. same with WN partners like hotels and rental cars. And individual hotel nights/car rentals get you 600 CPQPs points each, which will add up, even if you don't travel that much. Hop from hotel to hotel every night.

You should visit the Southwest forum and start reading.