Need a distro recommendation for a slow development laptop

I wish to set up a development environment on an older laptop I have. It's an Dual-Core Athlon 64 with 2 gigs of memory. This laptop has an amazing screen and keyboard, and considering 99% of my development is done via RDP'ing to my dev workstation it's fast enough for its primary job. Don't try to convince me to buy a new one.

I have some very specific requirements that are making this search hard:

1. Needs to be 64-bit. I realize 64 bit will be slower than a 32 bit machine at this spec level, but I need access to 64-bit toolchains.

2. Needs to support Full Disk Encryption. This is a requirement of my company.

Easy out-of-the-box FDE kills a lot of the distros out there, and from my previous experiences with linux 2 gigs of memory in a 64 bit graphical environment can flow out of water.

If XUbuntu supports FDE (I assume it does since "normal" Ubuntu does) then it seems like the right choice, but I'm trying to see if I am missing anything before I commit. I was also considering Fedora just because I'm familiar with RHEL, but I am not sure if it is suitable for a laptop of this spec.