Thanks everyone. As planned we spent last Sunday looking for a new family member and we were fortunate to find one. After 4 days of "Foster to Adopt", we made it official and adopted "Pumpkin", a 3 year old polydactyl calico/tortie mix.
I'm still sad and miss my Boots, but you don't replace a family member and forget the other one.
She is a little spitfire and quite the lovebug. It took a day for her to warm up to us and my other cat Hazel (brown tabby) is just an amazing animal. She loves all cats and was so good about giving Pumpkin the space she needed and let her set the timeline (they're already friends).