Sonicwall SSL-2000 vs SSL-200 VPN devices?

I'm trying to figure out what the major difference is between these
devices?

They both say unlimitted connections.. is this really true.. we have
42 users right now, but only about 10 use vpn (this will grow),
usually about 4 simultaneously..

I'm starting to think the 200 device may work for us, at a fraction of
the cost (though it appears that at least for x64 vista, client
software wont be out till 2008?)..