Thank you to all who responded.
I've learned from the supplier of my paper profile that it is "defined for D50 viewing". I've now got my studio lit with Phillips 5000K lamps. I know that that is by no means a perfect solution (CRI index of these lamps is 82) and I am beginning to realize that, especially with the paper I'm using, soft-proofing with LR is not a magic cure all, but a tool to use along the way to getting the prints to look like I want. I'm keeping my display calibrated to D65 because it's my understanding that this is the best way to go for editing images that appear on the web (since sRGB uses D65) and that is what the customer uses to initially judge the image.
I understand that there is a lot that will always be out of my control (such as the conditions under which the customer ultimately views the print) and that somewhere along the way I have to find a happy medium and then, as Mark states, "train [myself] to deal with the difference". As I'm selling prints to folks who will hang them under a variety of lighting conditions, I've decided that a professional viewing booth, even if it was cost-justified, wouldn't be all that helpful in this situation. So, back to the learning curve...