I really enjoy my job and value my career
^ This.
Many parents won't have been lucky or dedicated enough to build up career credit in this way. Others will but will feel they've now been there and done that and would like to try a slower lifestyle.
You've also said the role of SAHM doesn't appeal. Make no mistake, it is extremely difficult to restart your career after even a short time away to raise a family. If you know you will regret not sticking with things when the children are a little older then take this job now and work to develop unique skills that will put you in a stronger position to get more balance in the future.
Even if it turns out to be hell, you will have a both a stronger negotiating position and more opportunity to hear about other options in your industry from within the company.
You can also always just leave, knowing you'd given it a shot.
What ever you do, don't feel guilty about the other options or stuck with your decision. If something isn't working out you can change it. Parenting is such a long game and your family's needs will constantly shift. Your happy independent toddlers who would cope well with your return to work, may become very needy preteens!
I'm in a similar position to you in that I have small children and a high earning job that I don't do for the salary. Luckily I'm in the UK and have now reached the point where my level of expertise lets me call the shots to a certain extent.
With DS1 I didn't have that level of clout and had to work much more and inconveniently than I would have wished.
I really focussed on getting my skills specialised enough to negotiate more balance - for me this meant not going into a 'female friendly cul de sac' but staying in a tougher, male-dominated area for a few years. There were some really tough bits (for me!) when Ds was 2-4 yrs but it's done him no harm at all and he is now very proud of my job.
He fondly remembers coming into work on occasion and being watched by admin staff when I was working late into the night - he loved it!
Now with a preschooler and pregnant with twins, I'm pleased I stuck with it as I have the best of both worlds!