I see BetterRed beat me to it. I use
xplorer˛ from Zabkat too. Mine's reasonably up to date. It's relatively plain to look at but there are a myriad of options and lots of power for those that want it, or you can keep it simple.
I looked at Q Dir mentioned by Uncle Robin and it didn't float my boat, but given the description of your problem you may find it fits well.
I quite liked XYplorer when I looked at it some years ago, but at that time they were having trouble properly supporting 64bit systems (in a manner acceptable to me, anyway). I don't know if they have fixed that since.
I looked at lots more some years ago, but these were the pick of the bunch at the time and xplorer˛ was what fitted me best. I've updated with each of the major version changes - which has been often enough to give comfort that development is still happening, but not so often that the developer seems greedy.
Oh, and I second BR's advice. Full Windows Explorer replacement can be troublesome, I much prefer to leave that as it is and just run xplorer˛ like any other application.