I also plan to remove the upper cabinet to the right of the window and replace it with two or three open shelves, to make the space feel more open. Any suggestions?

Are you sure you can re-stain those cabinets? They don't look like like "solid wood". You can't sand and stain veneer.

staining is a lot of work (labor and cost). have you though about refacing them? a nice slab front? for the same money, you could get something nicer.

has anyone done a sample door for this 'darker stain' to even see if it looks good? Or to see if the wood takes the new stain? Why don't you do that first, and then match a countertop to that color?

If you go with the darker wood stain cabinet, I think that going with the cream color countertop and the light gray backsplash will be a good look. Unless you are wanting to create an overall darker look in the kitchen, I would keep the cream white countertop because that against the dark cabinets will allow the space to feel more open. To get an idea of this, I would go on pinterest and type in exactly what you are wanting to see inspiration photos! Good luck!

I would consider painting those cabinets, not staining....

don't think 3 shelves above the penisula will work unless you can reach them or unless they are just for decorative items.

Thanks to everyone for your comments and suggestions.

The cabinet doors are solid oak, an my dh refuses to paint them (and I also like the warmth of wood tones, especially during the cold Ontario winters), so instead we'll go for a darker, but not dark, stain (something in the line of provincial) to reduce the orange undertone. There is some melamine on the side panels, we will get it replaced with thin, stainable wood sheets, and will definitely ask for a sample of the stain both on a door and on the wood sheet before committing to the work!

And the shelves to the right of the window, except for the bottom one, will hold either decorative or seldom used items.