What do you mean you want a CMOS? CMOS is just a tiny chip of RAM, just a few kilobytes, usually part of the BIOS chip these days, where your BIOS settings are stored.
If you mean you need a BIOS chip because you had a bad flash, just do a search on Google, there are several companies that sell replacement BIOS chips, pre-flashed with whatever you need. Or contact Asus. Nobody in FS/FT is going to sell you just a BIOS chip from a board they have, unless they have a damaged board they're just selling parts from, which is rare.
However it may also be possible to recover from the bad flash, if you have a floppy drive.