Our local animal shelters often recommend (especially around Christmas) that if you are thinking of giving a pet as a surprise, to actually give them a "certificate" that you make up, redeemable for your company with the recipient to go look at prospective pets. That way you eliminate the risk of making the "wrong" selection.
Both of our girls were "rescues" - it was my first time adopting older animals and I wasn't sure how I would feel and how that would work out. After all, as you experienced, someone else has helped mold and shape who they are. Our poodle came from the local Poodle rescue association - given up as a "problem child". She was 14 months old, and she had been in a foster home for a few weeks so they were able to give us insight into her temprement (needs owners who can say a firm no, wants to be the alpha dog, etc.). Her first owners had trained her to always use pads in the house, but the foster home had her nearly perfectly housebroken.
We waitlisted with the local Westie association for a companion for her, but a firend of a firend of a friend needed a good home for a 4.5 year old Westie (owners moving to facilities that didn't permit pets). She had lost *all* of her housebreaking! (We'd been told she was housebroken but it got turned round by the time it was told to us

). Anyway, she got the hang of things within a day or two, and between the two of them we've had fewer accidents than one puppy would have had. (There's a great product called Nature's Miracle that uses natural enzymes to neutralize the odor and we have found it effective).
Sorry to be so longwinded - these are our "kids" and dear to our hearts as you can tell! I just wanted to share our experiences to say that after getting these guys, I don't think I'll ever adopt a puppy again. So often the older dogs (like our Kerry, who's now 5) have a harder time finding homes.
There are ways (like rescue associations) to adopt a dog that is older, and yet still have a good sense of their temperament and nature are, and often their background as well. Then you can be assured that the dog will be a good fit for *all* of the family. Plus, the associations will take the dog back if the placement does not work out, because they want you to feel completely comfortable with you new family member.
There is a great interactive "breed selector" at Purina's website:
http://www.purina.com/dogs/default.asp (click on the link on the left, just below the pictures). This lets you be very specific about qualities you are looking for, activity level, how much they shed, how frequently they have to be groomed, etc. and then produces a list of breeds whose temperament and qualities are a good match for your lifestyle. That's how we discovered, in looking for a companion for Ginger, that Westies would be a good breed for us to considre - and they were so right! At
www.akc.org, there are links for the breed rescue groups across the country and they often have beautiful loving animals surrendered due to divorce or a death in the family, and they help find these (usually older) animals homes.
Good luck with your decision - you are obviously very kindhearted, and I'm sure you could find a new four-legged family member that you all can enjoy. <The Westie is now reminding me that it's time for their dinner, so I am stepping of my soapbox now>