I wish i could play the original farcry with the graphics of crysis. I once assumed that someone would release it as a mod, but still no joy. Maybe im better off suggesting this at crymod.
You can't copy the assets from Far Cry because Crytek sold the franchise to Ubisoft. To make an authentic mod for it would take a huge effort and a long time, maybe even years if you want to recreate the levels as well.
I used to joke about making the old Far Cry MP maps for Crysis a long time ago. Wouldn't be hard if you knew someone who knew Cryengine. It's the same system. Just you'd have to remake the assets from FC.
Sitting> It was really good. But you'd be missing the epic multiplayer that went on back then. It's very Crysis-like in it's environment and gameplay (minus suit). I do really miss the machette though. Was a wonderful melee weapon.
The first 2 levels of FarCry were remade as a single (and big) map for Crysis. It's called "FCFort" You can also set the time of day at the beginning. You can find it at CryMod.