It depends on what you goal is for using a proxy and what exactly you mean by the term proxy. IPTV is a very big catchall name for a lot of different services. From what I have seen proxies are mostly used to allow say a smart tv to watch content it does not have a native client to watch. It seems it is mostly something you run inside your house not on a some VPS cloud device.
If this is something to bypass a geographical limitation on where you can watch a VPN function running a VPS is going to be simpler than some kind of proprietary proxy.
A VPS is going to be expensive to stream video through. It is pretty easy to get a VPS with a preconfigured VPN or you can easily load one of the many linux based VPN if you wanted to set it up your self. The big problem is cost for the bandwidth. The cpu load is almost nothing so that part is cheap but most these services have limits on how much bandwidth you can use or they charge xxx per gigabyte.