For the Toshiba C855D-S5103 I got it working with Snow Leopard (10.6) using distro SnowLeo DVD
You'll need to get the wifi kexts from osx86.net as well as the right audio kext, don't use voddohda for audio on this distribution.. it doesn't work.. you have to get the realtek kext from osx86.net - otherwise SLruns and it works beautiful.
No problems with USB, everything else worked.
Unselect UUID (you don't need it if you use the default bootloader)
choose Evoreboot with OpenHaltRestart, (both)
for chipset Use the option beneath Legacy AHCI
Use Vodoo powermini but use ApplePS2 (32bit)
If you need the full list I use, just reach out, I'll email it..