Without wanting to state the obvious the clothing system you use will depend on what you are doing, where you are doing it and the weather. Clearly the higher you go the colder it gets, so in some respects I guess you will be limited by your scooter.
The layering system would generally consist of a base layer, mid layer and outer layer (and anything you fancy in between tbh). The inner layers generally give you the warmth with the outer layer generally being a waterproof one, again depending on the weather. That can be good for someone with total mobility who may start a walk with only the non-waterproof layers but then at any sign of weather approaching stop and quickly don the waterproof layers, I suppose that may be an issue for you? You may be happy to start out that way, but the drawback there being kind of the opposite in that you are unable to take anything off easily if you become uncomfortable, ie start overheating due to the layers. The outer layer in the layering system being the waterproof one would generally be made from a Gore-Tex, e-vent type fabric which can cause a bit of condensation from within, especially if they don't have any form of vents in. I'm by no means a expert on those though, as its not for me and I'm sure plenty will tell you they are fine with those type jackets and that system.
I use a brand called Paramo which do things a bit differently. They aren't for everyone, but you see quite a lot of people using them. They use a different type of system which pulls moisture from within and repels it away from you. The best way may be to look at the website
and see exactly what it does! The drawback of Paramo is that it is a a layered system with an inner and outer layer, so if you run hot as I do when I'm out, you don't need too much on under it. Depending on the garment a lot do have good venting, so you can easily get some air flow in if you begin to overheat.
In essence everything will be some form of layering system, it just depends on how you go about it. I would suggest researching a good, local to you outdoor store and going along and having a chat with staff and hopefully they will be able to point you in the right direction for you. There is no right or wrong way, just a way that will be best for you.