I always recommend a sheet metal pan with a small overflow drain. They now make an alarm that can be added when water is present.

All your ideas sounds really good to me. I know nothing about drain pans but I do have one tidbit of advice.... make sure to secure the drain hose in the drain with a zip tie around the hose and the closest water spigot or water hose. My drain hose flipped out a couple of years ago and the mess was unbelievable..... as a result I got all new carpet it would make an awful mess if it happened on a second floor.

If you're renovating to the point of adding a bathroom nearby, and thinking about using tile in the laundry room, you could also get a floor drain installed in the laundry room instead of a pan. We built new and have a drain installed right under the laundry machine.

What dazureus said. Drain pans are nearly useless. Since you’re starting fresh, or near it, I would put in a floor drain, tile the floor, and tile up the wall 6”. Frame a nice box into the studs to recess the dryer vent. If possible, make yourself a good cleanout access for cleaning the ductwork without pulling the dryer—ours is in an adjacent closet. Be sure your shutoffs are easy to reach, install ball cock valves, and use the best braided supply lines money can buy. If this is your forever home, these are small investments that will give great peace of mind. Good luck.

I would waterproof the floor. Take a look at this thread Best Way To Waterproof Laundry Room Floor in the Bathroom Forum. Remember tile and grout are not waterproof.

Good point on waterproofing. We actually used a piece of commercial vinyl flooring. The drain is under the washer with shut offs in a semi-waterproof box. Still, if we had a big leak, it would likely hit my baseboards and soak into the baseboards and get into the subfloor. But I do feel it unlikely to get downstairs. If I had it to do over again, I would tile.

While the examples of the laundry set up posted by @dazureus is lovely, I would want that shutoff valve above the counter, or in the sink cabinet. The way it is set up now, you have to pull out the washer to shut it off. I shut mine off when I'm not using the set and turn it on only on the days I do laundry. I have another laundry area that I turn off when we leave for several days, but it is a little harder to get too, or I'd shut it off most of the time.

The wall dryer vent is only accessed with removing the dryer from its spot, another difficult situation, unless there is another access point in the wall behind the dryer. Dryer vents need cleaning regularly.

Just wanted all to know that I decided instead to put the laundry room where the main floor powder room used to be instead of upstairs. The whole point of moving the laundry room was to allow the former laundry to be converted to a 3/4 bath to allow aging in place. The result is a laundry closet off the kitchen and main entry hall. It's on concrete slab so less leak concern than an upstairs laundry would be. The upstairs will have a bathroom added instead. Three bedrooms, each with its own bathroom.

do you have any pictures of your new laundry room? Id love to see it.