You can flash from bank 2, but I'm not 100% sure if the bank switch should be set back to bank 1 once FlashBIOS is loaded. I believe this is the case, should start writing at the beginning of the chip.
Rembmer, there is no 1MB X2 BIOS to "get." You need to build it on your own. Refer to the X2BM tutorial I pointed you to, replace the two loads of X2 4983 BIOS with a single load of X2CL. (Put FlashBIOS in the other banks for recovery if needed.) Also, you got 2 bin files in the X2CL archive, 1 for 1.0-1.5 xboxes and 1 for 1.6+ xboxes. Be sure to use the correct one for your box!
There are two versions of FlashBIOS, I copied from the Team Xecuter download area-
FlashBIOS v3.01
Legal utility for updating your X2 or X3 mod with another Bios. Works on all versions except v1.6b
FlashBIOS v3.03
Legal utility for updating your X2 or X3 mod with another Bios. Works on all versions except v1.6
On my 1.0 xbox I'm pretty sure I could load both of them without issue, I would think the same would be true up through 1.5. Only is a problem on the 1.6 and up boxes, it's an either/or deal it seems.
The config file will go on your E (or F if you've got it) partition on the HDD. The settings in there control the boot characteristics of the BIOS. What colors it uses, what dashboard it loads, etc. (if you don't know what a dashboard is then you've got more research to do. this is important.) There are a couple utilities available to assist in editing this file, but it is only plain text and can be edited in a text editor like notepad. Check out the X2CL specific forum for more info, read through the stickies.
-Whoopin'