Thats the way I envisioned it too, with proportional control. There may be controllers out there that can perform this, but mine will not.
The controllers were like $23 each on ebay, the thermocouples were $10 each, the relay board was $10, and the buzzers were $2 for two.
Total $46+$20+$10+$2= $78 for Control setup. Fans are gonna be like $300.
You can quickly see how fast this adds up. The Thermal management products would have been double this, but would have been turn key and a little more polished. I prob would have used a commercial offering(fan solution) If I felt they would have worked but I'm pumping this air 15-25' to dump in another part of house and just didn't feel those offerings had enough CFM.
In other news the new seating position is working well. I was able to make some improvements with mid-bass response by moving them forward 2ft. I also moved the mains closer to front wall and blocked their ports. The ports were rear-firing and I didn't need all that port energy bouncing off front wall and contaminating the my response. It worked well.