PP here. It was Carnegie Kitchens. Yes, they can do your other stuff as well. There's a process.
Ikea has a national installation service called Traemand. Traemand's process is cookie-cutter, assembly-line. You sign a Traemand contract, you get the basic cabinet installation for the Ikea-guaranteed price.
Carnegie can do whatever kind of carpentry you need. They knocked out a non-load-bearing wall for us, reinforced a half-wall in its place, took the floor all the way down to the joists and then re-built the subfloor, and moved a wall and door for us elsewhere in the house. All of that work was good quality and as far as I could tell reasonably priced. But because of Ikea's deal with Traemand, they won't give you an estimate for any of that, or sign a contract for it, until first you've signed the Traemand contract for the basic cabinet install. So then you have 2 contracts, one with Ikea/Traemand (national) for the cabinets and one with Carnegie Kitchens (local) for the rest. There were some communications issues, and some scheduling issues, but the quality of the work was good in the end.
None of the extras are covered in Ikea's design deal. And Carnegie will not give you design or working drawings. If you need drawings, you need an architect. Our work was done without drawings, but it was very simple. I wouldn't do that if you're changing a footprint or doing anything complex.
The Ikea countertop installer is Norwood. We heard some bad things, mostly about scheduling, but our experience was almost all positive. The schedule was good, the installation was precise, and the counter looks good from above. They patiently worked with us while we got one custom angle particularly right. My only beef is that on the bottom of the counter, there are stenciled-on markings (like there are on plywood) that they did not bother to polish off -- I guess figuring no one ever looks at the bottom. I didn't notice them until the job was done, all the papers signed, and they were gone. Now no one ever sees that stuff (unless they're on their hands and knees looking up), but I know it's there. Grrr.
I think Carnegie's carpentry and cabinet work was excellent. I wish we'd used them for the tile work; our tile installer did a poor job and by the end I came to trust Carnegie's guys better. But as I said you're on your own for the plumbing, electrical, HVAC, and floors. Their recommended plumber was good; their recommended electrician not so much; and we used our own floor people, but I'm not sure -- I think using theirs might have been a better move for better coordination. They really wanted to be hands-off about the HVAC, which was frustrating because we ended up paying a lot on that end on our own for just a few key pieces. At the end, when the exhaust hood had to be hooked up, there was a carpentry piece to it, an electrical piece, and an HVAC piece, and no one wanted to touch anything that wasn't their specific thing. I was like, really? I have to have three different trades in the room at the same time, to do something that's really just twisting a couple of wire nuts and taping the duct in place with flash tape?
We got through it but the multi-sub coordination was a hassle. Like I said, you will be your own general contractor. Be prepared to be very involved, on a daily basis, or to have unforeseen stuff happen that you didn't know to ask about.
The alternative, though, is to hire a general contractor or project manager to do that stuff for you. For your very small kitchen, you probably don't have that $$ in the budget. This is the tradeoff you make. We would do it again, but have your eyes open to how much time and energy you are going to spend in place of money. And if you're not a handy type, how much you are going to have to learn.