Photo hosting providers usually have free and paid plans, so you don’t even need to pay to use them. Unfortunately, your clients will be paying the price for it by seeing ads when browsing your portfolio. It might be okay for a beginner but does not look very professional. If you get a paid plan, you will be able to use the provider's interface only without the ability to install something else.
You’re paying more, so there SHOULD be a minimum uptime guarantee and better server speed. Look for a host that offers 99.5% at a very minimum, although ideally, I’d rather go with someone who offers 99.9%. Search through some reviews as there are many who have put this to the test. For example, any of WHSR’s many web host reviews include an uptime record as one of our key tests.
Unmanaged VPS plans are available with a number of virtualization frameworks and hypervisors, with most users looking for "bare metal" isolation for increased security. Microsoft has also developed the Azure cloud platform for Windows servers on VPS hosting plans with elastic scalability that rivals AWS or Kubernetes. Windows is used frequently in private/public cloud orchestration for enterprise IT, whereas most small businesses running Windows servers for ASP.NET apps choose "bare metal" VPS plans.
If you are familiar with hosting control panels, shell commands, and you have basic server administration and troubleshooting skills, then unmanaged VPS is the way to go. Note that while you purchase self managed VPS, you should be capable of managing applications, software, services installed on your VPS. Also, you must know installation/uninstallations, resource monitoring, server performance tweaking and troubleshooting of any technical issues.