The “best way to do this” is to get your own bare metal server hosted with a proper company (think IBM).
it won’t be as expensive as $25 a day, but its surely around $250 a month or so. You’ll be limited by the GFX you place on the server, the software you choose for the server and so on.
the better option would be - if you had a t1 line anyway - to host your own server from a proper gaming computer with plenty of ram/processing power in order to handle multiple contemporaneous clients.
I believe you would need to virtualize in some way to provide access to more then 1 client, but not many VM software out there that can share gfx memory adequately so that may also be a challenge.
Why not just build specific visualization packages in Html5 mode? You’ll obviously have to dump out a lot of detail and build things properly like if it was a game to get any sort of decent performance on a web browser, but it isn’t impossible…