ComputerDoc said
Been doing CCTV using analog/digital BNC etc for quite awhile now
Have new business customer with 2 buildings
one on each side of the street
looks like   WIRELESS is the solution

but don't know what I don't know about hooking wireless cams
to a wired DVR system
do you guys have any advice

This is the best solution I can recommend for send the signal to another building.  In theory if the system is small enough you could even do it with an 4-8ch dvr. 

https://www.securitycameraking.....tp-locom5/

https://www.securitycameraking.....-prd1.html

Here are our wireless cameras but they're distance may not be adequate enough for a seperate building.  

https://www.securitycameraking.....2IREW.html

Alternative you could mix the two solutions use the wireless cameras with a bridge and another wireless router and have the base NVR at the business.

If you have any further questions I am available by phone directly at 1-866-573-8878-ext123