You don't want to have a partial denture if you can avoid it. You will loss bone mass (alveolar bone resorption) wherever there is no tooth. Implants done properly are a good thing; nothing is as good as retaining healthy natural teeth, however.
I have firsthand experience with this issue and have absolutely no regrets after having four teeth (lost due to dental trauma- I was hit by a car) replaced with dental implants twenty years ago. Prior to that I had a removable bridge for ten years and suffered significant bone loss because of the lack of teeth in the jaw bone.
Regarding root canals, if they are done properly, they will last a long time and will not cause any problems. An endodontist with an excellent reputation is the one to see for this. It beats losing the tooth altogether.
I don't understand why root canals were done on the two teeth if they were healthy; how is it standard procedure???