I am a former BIOS developer but even if you paid me I probably still couldn't be bothered. Just to let you know how big the ballpark is, a fully custom BIOS port from scratch might cost you $40000-$60000 (depending on the level of customization). Been a while since I worked in that area though...
You can use the Intel Integrator Toolkit to modify most of their BIOSs (including yours). This is intended for enterprise IT admins, OEMs and embedded developers but anyone can use it. You can changing the boot display image (if supported) and default settings but you will not be able to switch...