It must be either system-related or a bad installation of the modpack or FTB, because on my system this is literally one of the fastest loading modpacks of all the packs I've played. It's less than 30 seconds from the time I click Launch until the time I can click Single Player and enter my world.
EDIT: Aaron, ignore what I wrote below, I didn't see you only have 4GB RAM installed, so you shouldn't use those java arguments. Just set your RAM Maximum slider to 2.5GB and see if that helps you.
I should add I do have a lot of RAM and am using j8_11 (which is an older version and not recommended since it doesn't have all the latest security updates) with
these java arguments. Note that they're only recommended for systems with 8GB of RAM or more. That's prob why mine loads so fast tho, honestly. But worth a shot perhaps. Even if you're still using j7 (which is recommended for FTB), you might want to try the j7 argument string and see if it helps any. I don't use the last "IPv4" argument because that really only applies to people running SMP servers I think, not SSP.