I would not be a client.

An AWS is about US 10 per month ? So that is rather expensive compared to the online services. The online services have you choose very easily between different countries. A bit more difficult / limited with AWS ?

Will the 'login' ip address always stay the same in your setup ? (I mean in case I stop the remote machine and later start it again).

On the upside: AWS is probably more secure (no man in the middle possible) and maybe faster ?

First you should make a good description of those 'people' who want to run their own vpn. What are their reasons.