I want to be sure I order the correct lockset.

Sure, check out our 82-081 handle set. I think you'll find this matches quite well.

You also mention that your door is harder to open. If that's the case, it would only be a matter of time before any replacement handle you get breaks, too. I would carefully look over your rollers and track to make sure they're functioning properly. Check for dents or debris in your tracks, and confirm that the rollers aren't clogged up. You may even need to replace the rollers entirely.