Sounds like a great idea... I had no idea what "newel" posts were named but that is exactly what I was looking for and did not realize they came fabricated. I had to google the newel post and the wainscote with handrail and I found this link for anyone else interested. Here is a link that might be useful: tight staircase wainscoting handrail project

I just took the plunge and painted our orangey oak bannister a few weeks ago. I barely sanded, then used Zinsser primer, and then painted with a Rustoleum shiny black (BM white dove for the spindles). It's fantastic and has held up to 2 messy big boys without any problems so far. I also wondered about staining vs. painting, and searched the blogosphere without any clear answers. In the end, I figured painting would be easier and there was nothing worth preserving about my bannister. I had a trickier time with the balustrades (is that what the spindles are called.) This was mostly because I was rushing, I'd underestimated the amount of time it would take to do an even job. One good tip that I read on a blog somewhere - use a kid's paint brush to do some of the tricky spots where the spindles meet the bannister. I'm still in the process of painting the surrounding rooms (I can only do it while my kids are at school, and when I can get a day away from work.) But doing the bannister was such a pick-me-up - a great result from not too much of an effort. I sometimes overthink these projects, and this one motivated me to do some more DIY fixes.

It is becoming increasingly more difficult (and expensive) to get oak handrails that are made from a single, non-jointed piece of wood. I've had experiences where I've done a special order specifying non-jointed wood and ended up rejecting and reordering the rail because I kept getting sent jointed material. The last time I ordered was about 1-1/2 years ago and I got what I wanted. The lumber store could supply pieces up to 16' long and the cost -- based on profile and beefiness -- ranged from about $8/ft to almost $20/ft. I wouldn't be surprised if it was much more expensive in this post-covid world. I can't say if your contractor is lying. It may simply be that the supply of unjointed material is non-existent at the moment. As for the conditioner, it won't get rid of the lines, but you will get less contrast between those jointed pieces when the stain is applied, and the darkness of the stain will help hide the actual joint. It won't be invisible, but it could be made significantly less noticeable. I'm not saying you should be happy about this, but your supply options for higher quality may be limited depending on where you live and what is happening with suppliers.

Houzz won’t let me edit my post.. the carpet is being replaced with a TBD neutral. Can’t do wood stairs at this time.. plywood is under carpet.