Well, as far as evox goes, I always prefer to install it manually rather than risk a trojan with slayers or have something else do the work so I don't know what goes on in the background.
About your chip. I haven't had any experience with them and would strongly advise asking the place you purchased from regarding its specifications before flashing the wrong size bios.
And I assume if you want to flash the bios you have on it now isn't doing what you want it to do, because if not, flashing would be a waste of a chip if it goes wrong (which isn't all that often if your chip is installed correctly, but apps do crash sometimes in mid-flash)
In short, to boot anything from a CD or DVD it looks for default.xbe, so take evoxdash.xbe from your evox package, rename it to default.xbe and modify the evox.ini to your prefs, make an xISO burn to a disc (this is not such a tough one if you have a samsung drive) DVD-R if at all possible, if not then CD-RW works best as far as CD media goes. Once you get it to boot you can ftp to the xbox to manually install it.
Evox M7 bios I use autodetects evox from the C: so I just uploaded evoxdash.xbe and evox.ini to the root of the C: and voila, when the chip is on, I get evox, when it's off, the MSDASH.
Hope this helps.