You need to talk to the Endodontist and see what the long term prognosis is. If he thinks he can treat it and you're good for life, and money is no object then you might as well treat it. If he is just putting off the inevitable then rip it out.
If/when you get the tooth extracted then go the implant. I just got a couple of implants and they are pretty good. Don't wait too long (i.e. decades) to get the implant.
I had the abscess, root canal, crown thing about 30 years ago. Eventually the tooth was removed and I had a maryland bridge, which was fine.
DO NOT UNDER ANY CIRCUMSTANCES CONSIDER A PLATE. Having a false tooth on a plate is absolutely the worst thing there is. I had one for six months while my bone graft and implant healed.





Over the years the bone and gum recedes. When I finally got an implant the surgeon had to do a bone graft to get enough bone for the implant. Bone grafts are easy and effective. Fixing receding gums is not so easy. Periodontists say they can fix it but the other surgeons were not as optimistic. Receding gums are not a huge problem unless you show a lot of gum when you smile.
Implants cost about $6000 each, including the crown that goes on it.
I had my implants put in by a oral and maxillofacial surgeon. Periodontists and dentists can also do the work. The surgeons are specialists in major facial and jaw surgery. The dentists and periodontists are guys who have done a training course. There is not much difference in the price.
BTW. When I had my maryland bridge removed after 30 years there was no significant damage to the adjacent teeth. One tooth was crowned because it was broken when I was a kid, the other was just filled a little at the back and is as good as new. I'm told maryland bridges only last 10 years or so. I got 30 out of mine and the only problem with the gum and bone receding underneath it.