I often get emails asking for a paperhanger recommendations for XY&Z cities and while I don’t have a running list of every paperhanger in the country (or world!) my answer is usually always the same. I do highly recommend hiring a professional paperhanger when hanging wallpaper. While you could potentially do it yourself hiring a paperhanger will save you a lot of frustration now and down the road especially if you end up installing it wrong. This is an area that you do not want to skimp on. A reputable wallcovering installer will will carefully prepare a comprehensive plan, estimating costs based on material, labor and experience specifications. They will also be able to help you determine how many rolls you will need to order and any questions you may have about the installation.
I always recommend people take a peek at the National Guild of Professional Paperhangers website and find someone that way. All members of this association are craftsmen and women who install wallcovering for their living. It is important to find someone that comes recommended and has a reputation for excellent work. If you are in the NYC are I am more than happy to send over info for reputable paperhangers in the area.