Which hosting providers do you recommend for Combu?

Searching the web for "a2hosting review" it seems a decent satisfying hosting provider (standard hosting or VPS? it depends on how much traffic and space you think to reach, but you can perfectly start with the inexpensive standard hosting and see how it runs).

About AWS the answer is "yes you can use Combu on AWS", since it's a virtual machine then you'll need to install and maintain everything by yourself (Apache and MySql) but it's a very good option, and anyway it isn't that hard to install the software:  http://docs.aws.amazon.com/AmazonRDS/latest/UserGuide/TUT_WebAppWithRDS.html

About Google Cloud I know nothing, but I read it provides "Cloud SQL A fully-managed MySQL database service", though I don't know anything about it and neither about eventually the web server hosting your PHP files.

Only thing I can recommend is possibly to avoid using the same space for both website and Combu (or any other external application), mainly for security reason, because if someone hacks your website at least it will not affect your game/app (and viceversa). A good option could be to have Combu (and other external applications) running on AWS or similar providers (virtual machines where you spend per usage) and your website running on an inexpensive hosting provider. But it's really up to you, you can perfectly run both website and Combu on the same hosting as well to start, my concern was just to maintain different for security.

Thank you very much for your complete answer. Several points are very useful to me, like this recommendation to keep the website and the hosting of Combu separately, I had not considered it and I certainly find it very reasonable.

If in this evaluation process I find something that can contribute to this subject, I will comment here, in case it is useful to someone.

Thank you!