1946 is even cheaper on Amazon, and you'll obviously use the SUBSIM.com link...
I'd recommend plumping for 1946 over the original, it's like a squillion games in one - alright, a handful - and then get HSFX5 (and patch) and UP3+DBW, all three are supermods, HSFX is great for online and UP3+DBW are best offline, I think HSFX and UP3 both come with JSGME so mod control is easy. UP3 needs to be (iirc) there for DBW to run, but worth it.