Pink -
Your DH is right. It will probably be a lot more cost effective in the long run to get a more fully-featured machine up front. But you do need to test-drive. I was all ready to buy a Viking 875 until I test drove it. I didn't like the feel of it (personal opinion, everyone!) but the minute I sat down at the 7700, I felt it was a very substantial and strong machine. I'm sure the 6600 would feel much the same. But it's your machine and you have to like its feel.
Just a comment on the Janome table, my - again - personal opinion is that it might be a little inadequate for handling large quilt tops and FMQ. You could butt up other tables but you might want to consider other larger spaces. JMHO.
Cathy