Interesting scenario. I know of no ideal, one box solutions.
But, I believe you could approach this somewhat differently, and it could turn out even better (I know, someone re-engineering the wheel
How's this; Buy the ubiquitous Velodyne SMS-1, utilize it for high passing your mains and alleviating un-necessary and undue strain with them. Then via the low side you've got an outstandingly versatile manual or fully automatic EQ with the great SMS-1. It comes with a mic, cable, mic stand etc,. It really is a terrific product. It's had updates and refinements throughout over time, and still today, it possesses a strong feature set and performance and the price has steadily dropped little by little.
Additionally, it's truly wonderful to have both;
a.) various EQ curves that you can pull up at the punch of a button
b.) also subwoofer system volume control at your finger tips
This product has sold thousands of units. Upon it's release, it was heralded as the greatest thing since sliced bread by all the audio press, ...being it was ahead of it's time and essentially, the first of it's kind. It's really stood the test of time. I bought one to experiment with a couple years ago, it's great. There's so many user guides out there too.
So, unless there's some aspect that I'm not familiar with, I think it could perform the tasks you need. heck it out and see what you think.
Still, you're going to need an amplifier, there's many inexpensive, high performance subwoofer amps. I don't know exactly how much power you need, but Behringer's offerings, either I-Nuke, or EP2500/EP4000 would be fine. Crown's similarly priced offering would be great too. If fan noise is an issue, look at Yamaha's inexpensive amps.
Good luckbtw; be mindful of upgrading to dual subs, so you may buy amp accordingly