Whole disk encryption with a Windows only Bootcamp

I've purchased myself a Mac Book Pro Retina (Haswell) and after giving Mac OS a fair shake have decided to go full Windows 7 and Bootcamp. There is no Mac OS install left on this system.

I am now looking for a way to encrypt my entire hard drive. My requirements are simple:

• AES based whole disk encryption (to take advantage of AES-NI)
• Ability to boot by just entering a password

I've looked at the following:

• Truecrypt is a no-go because it is not recommended for use with SSDs
• Bitlocker is a no-go because there is no TPM in this system and I don't want to haul around a USB thumb drive with me every time I have to boot.
• Symantec Whole Disk Encryption appears to meet all of my requirements

Before I drop $100 on Symantec I figured I'd ask the exerts if there is any other software out there I can use. I prefer Open Source but understand that might not be possible.

It's worth noting that BitLocker can be run without needing a USB key. More information can be found here, scroll down to "Use BitLocker on a Drive Without TPM."