I spent many years working on high-end TV weather graphics on SGI Indigo, Onyx, and the O2 (toaster over shaped) boxes; they were remarkable for their time and the hours and hours it took to render graphics made for really nice downtime at work letting me say things like "sorry, can't do anything, graphics are rendering".
The best source for hardware ended up being a local university surplus shop where we could get the big SGI monitors for pennies on the dollar.