You had better get an 060 for videos.
My 060/50 is just watchable with MPEG1 and RiVA.
a 66 or 80mhz 060 would probably do pretty well... You'll still need a high-powered PC to convert things to MPEG1...
I think he is planning on converting and watch in hamp, then a 030 card will be good enough for watching movies.
Also he do not need a high powered pc but it will take a lot longer time to convert on a old x86 CPU.
@AmigaClassicRules - keep in mind that a 040 runs really hot so no trapdoor and higher rubber feet is recommended if not towering the miggy.
A 060 and 030 runs cool tho.