I have a late 2007 MBP too (superdrive removed) and was never able to boot and install an OS straight from USB(tried refit and refind too)
, be it clonezilla, Win 7 32/64Bit; only OS X works via USB. (Windows via superdrive worked flawlessly).
Luckily I had an old winclone backup I could use, when I replaced the SSD last year.
Is the EFI in newer MBP still that picky?
Did you have success with this tool?