I don't think that the SS has to match all around the kitchen. It's personal preference, but many prefer that it doesn't.

As to the 40" -- there's no obvious answer. Yours is not a unique choice, but most lines jump from 36" to 48" and you'll likely have many fewer choices down the road should you want another range that matches in size. Moving things around again is a pain, and an expense, and the DH is right to bring it up as a question. OTOH, that may be quite a few years down the road, and it's often possible to shift things a bit without redoing the whole kitchen (depends on the space, obviously). So, yeah, it seems like a real issue -- but how big an issue and how the two of you resolve it is up to you.

No experience with the 40 inch range but a couple of comments.

I personally gave no priority to matching the stainless or handles but if that is the kind of thing that bothers you, then you should.

Have you tried your pans in the smaller oven? Can you fit a 9x13 with room for the air to circulate?

We actually liked moving the MW away from the range. I have a shelf built in the cabinet for it. It is by the frig so the someone can heat something else and not be in my way cooking.

Good luck with your choices!

Thanks for the input, I think you always second guess yourself when undertaking a large project and it nice to get some opinions from an outside source! I think I am sticking with 40 inch - the side oven takes toaster oven pans - which is great, I can now get that off the counter! If it needs replaced down the line the so be it, get what I want now! As far as the hood, I will keep looking. Check one choice off the list!

40 inch is a classic size for older vintage ranges, even if it is uncommon now. If nothing else, if you ever win the lottery a LaCanche Cluny, Volnay, Vougeot or Chagney would slip right in!

Seriously, I have seen the Kenmore and it looks like a really nice machine, especially for the price. You should definitely go for it if you like it. Worst case scenario you can always get a smaller range and fill in the space with an unfitted cart or something.

My MIL got the range you're looking at in her new kitchen. She thought she would be able to get two ovens but not pay the big bucks. Unfortunately, she's disappointed two years later for a couple of reasons. First, and this is her fault laying out her kitchen, the smaller oven's side swinging door hits the cab next to it. Second, only loaf pans fit well in the smaller oven. She thought she'd use the smaller one for most cooking, but finds she hardly ever uses it because not much fits in there. Have you seen it in person? It is small. I suggest you take your pans to Sears and try them out.