I own a few types of snow shoes, I think the best style to get started with is the type with a rigid plastic deck, e.g. MSR Evo. That style is a good combination of comfortable, lightweight, good grip, and not too expensive.

I would avoid the cheaper style that is basically ametal tube bent around the circumference (there are many versions of this style). Those are not as comfortable and provide only minimal grip in my experience.

Unless you know you will be in breaking trail in deep powder I would round down on the sizing (size is based on your weight). You really don't need all that much floatation and you are less likely to trip or stumble with a slightly smaller size.

I'm not sure what you mean by "fixed front toe box", all the ones I've ever used pivot. I see no reason to use the old-school style that is fixed to your foot. Also, boots don't really matter, you can wear any hiking or snow boots that are comfortable for walking. No need to buy something special.