I think that would be a great idea.
A rescue will need all the time, patience, knowledge and horsemanship you have to offer and you seem to relish a challenge and have oodles of commitment and calmness. It'll be one VERY lucky horse and I look forward to hearing all about it, when you are ready to begin. There is certainly no shortage of candidates
What would you be aiming for long term? Not sure whether jumping was just for fun or something you wanted to pursue?