Each state has different laws. In Ohio, if the purchase and install is by the same place, no tax. If we purchase and install ourselves, we get taxed.

So, email your state tax department and ask. That way you have the response in writing if they try to charge you tax when they shouldn't.

OK, it seems we should not be taxed: For other NJ residents....

http://www.state.nj.us/treasury/taxation/pdf/pubs/sales/su2.pdf

Capital improvement means an installation of tangible personal property which increases the capital value or useful life of the real property (land or buildings). The item(s) installed must be permanently attached to the real property.
Capital improvements are exempt from tax with the exception of the following: certain landscaping services, carpet and other floor covering installations, and hard�wired alarm or security system installations.

Exempt Capital Improvement Services. When the work performed on your real property results in an exempt capital improvement, the contrac�tor may not collect sales tax from you on any charges (materials or labor), provided you give the contractor a properly completed Certificate of Exempt Capital Improvement (Form ST�8).