Louisa is definitely a keeper. It's an underused classic feminization that hasn't even shown up in the top 1000 in awhile. It's very close to the perfect classic. My only concern is that I would not pair it with Augusta or any -a ending name since it would sound redundant even if it is a second middle name.
Thank you all so much for your input :) alas, it seems that for hubby there still is no name that holds a candle to Caroline Augusta Jane....
Also, upon further inspection, Rollo is right... With our last name, Louisa isn't as smooth of a pairing... But oh how I love Louisa, she goes on my short list for sure!