NETGEAR N900 DUAL BAND GIGABIT ROUTER WNDR4500 Problem

Any range extender should work but there are a few factors that may determine the best model to use.

• Range
  
  Each extender will be different.  Models with external antennas generally but are not guaranteed to have better range.  500 feet is a pretty long distance to traverse so placement may be important.
  
  
• Speed
  
  There are 3 speeds to consider.  The speed required in the shop, the speed of the router and the speed of the Internet service.  If your Internet service is low speed or you have modest requirements in the shop, then you don't need to be too selective about the extender except for the range, of course.  
  
  OTOH, if your Internet service is fast and you need as much speed as you can get in the shop, then you'll need an extender that can leverage the most the router can deliver.  The WNDR4500 is an 802.11n router and can do 450 Mbps on 2.4 GHz and 450 Mbps on 5 GHz.  The EX6400, EX7000 and the EX7300 should all be able to link at speeds up to 450 Mbps.  Actual speeds will probably be much less due to the distance.  The other Netgear extenders can only reach 300 Mbps using 802.11n.  If you decide to keep the R6400, the above extenders can use 802.11ac and connect at speeds up to 1300 Mbps.  There is, however, no guarantee that an extender can connect across 500 feet using 802.11ac. 

I hope this helps you make an informed buying decision.