I agree real wood is the best choice unless you have big dogs but it will depend on the budget I guess.I have no idea why you could not use the vinyl on both floors though.

Hardwood floors are very nice if budget permit it you should get a few quotes from some good wood floor companies in your area.

It is nothing wrong using the same material on 1st and 2nd floor.

J Design Group
225 Malaga Ave
Coral Gables, FL 33134
Ph: 305-444-4611
https://www.JDesignGroup.com

The reason I’m considering vinyl wood planks is because I also want the wood look in the kitchen which if I have water spills and leaks it would be much safer than real wood and my home is near the ocean and I don’t know if the atmosphere would be bad for real wood

Vinyl 'wood planks' look nothing like real wood. Obviously fake and dead. Real wood has life, and the color changes as you walk across it due to refraction in the fibers and finish. Vinyl doesn't do that.

Use hardwood or engineered wood will last you forever.

Vynil floors do off gassing. Even the fancy ones. I would avoid them, no matter how pretty.

Consider using a tile that mimics the look of wood.

Like what off-gassing, and in what amounts and for how long, zealart?

Get a good quality engineered wood product - check out www.Realwoodfloors.com or www.gohaus.com. I've used both products in whole house remodels and love them - including in the kitchen. Spills are no big deal. First photo (galley kitchen) shows flooring from GoHaus 7.5" Victory European Oak, the second is from Real Wood Floors Gallery Collection, Louvre.