I downloaded the latest daily build but it's not there for my Player
The ReplayGain support is not for the Archos version (yet) AFAIK.
a Cross-Fader which I assume is also not for Archos Players
Correct. The Crossfade feature is for the music players with software codecs, which right now mean the iriver h1x0 series only.
And no, you don't need fancy hardware to do crossfading, you just need proper working code.