Moving from SS 2 Days a Week to 5/3/1

I am 55 and several months ago I started lifting again following the Starting Strength program 2 days a week.

My starting lifts were:

Squat 75lbs 3x5
Bench 85lbs 3x5
Press 45lbs 3x5
Deads 115lbs 1x5

My current lifts are:

Squat 185lbs 3x5
Bench 140lbs 3x5
Press 100lbs 3x5
Deads 225lbs 1x5

I am starting to feel a little beat up and suffer arthritis and have had past shoulder and lower back problems that are starting to aggravate me. I have taken a week off and feel better and have decided to follow 5/3/1. I still like full body and want to lift only twice a week and was thinking of follow this.

Mon.
Squat 5/3/1
Bench 5/3/1
Chin/DB Rows

Thurs.
Squat 40%/50%/60%x5
Press 5/3/1
Deads 5/3/1

Does this look ok and do you have any suggestions?

Looks great to me. Go for it!

Thanks.

Another question. I want to start adding conditioning. Right now I just walk about 45 minutes 3 to 5 days a week but I want to really get in at least a couple of more intense days in. Like I mentioned with the arthritis hill sprints, jumping rope or any kind of running is out. I have tried them all and they kill my knees. I am thinking about getting a Prowler but I will still only be able to walk it. Any other suggestions for some high intensity conditioning without tearing my knees apart.

sledgehammer, KB swings, med ball slams, swimming, biking, battle ropes, weighted vest walks; you have dozens of options.