FPCUpDeluxe does have a 64bit option, but it doesn't work for Mac.
I can't remember his name right now, but the guy who runs it said it's on his todo list, so at some point we'll get support for that.
Apart from that, I love fpcupdeluxe, I have crosscompilers for linux and windows because of it and it works really nicely, with 64bit compilers for those platforms.
I don't know how to build 64bit FPC with crosscompiler support myself, and I need cross compilation more than I need 64bit at the moment :/