The option of the flap surgery is not a bad idea as an alternative to bed rest. You just need to know what you're getting into with the surgery. It should look something like this:

1. Make sure there is no infection. If there is, you'll probably need approx. 6 weeks of antibiotics to clear that up first.
2. Your recovery should consist of 6-8 weeks of 24/7 bed rest in an air-fluidized bed. That's laying flat. No sitting up. No getting out of bed for any reason whatsoever. Your diet should also be high in protein to aid in the healing process. This is usually done in some type of skilled nursing facility since it is hard to get the insurance to pay for this type of bed for in-home use. For your well-being, you need to stay on top of the nurses to make sure you're getting what you need. Unfortunately these days those places are understaffed and the nurses are overworked so you need to advocate for yourself.
3. Your rehabilitation should be, based on my experience) 2-3 weeks of incremental sitting in your chair again to acclimate yourself to adding pressure to the site. At the same time you should also be transitioning to some type of LAL overlay mattress. You'll probably also start to do some endurance and strength training since you will loose a lot of that from you recovery time.

I've gone through this three times. It's neither pleasant nor enjoyable but it works and its better than the alternative of potentially never ending bed rest. You know that there is an end date at which point you can start to resume your life. You just need to mentally prepare yourself for the down time. Find things to keep you busy (work, read, etc.). Make sure you have a in-depth conversation with the plastic surgeon about how all of this will look for you so you are completely clear about all aspects of the procedure and recovery.

All of that being said, you also need to address the root cause of this problem. There's no point in going through all of that just to have it break down again. Definitely shop around for a new cushion. The collapsing air pyramids was one of the issues I had with the vicair that caused me problems.If you can come up with a viable solution to prevent this from occurring again, I think you should give the flap surgery serious consideration if your surgeon is in agreement.