I wanted to differentiate my Isengard Warg Rider unit from Mordor Warg Riders. To do this I used 40k Fenrisian Wolves instead and gave the orc riders Uruk-Hai heads and shields. Then I painted the riders in a more Uruk-Hai like colour scheme and dry brushed the wolves in a uniform black > dark gray > light gray.
As usual my LOTR figures are based for my own in-house rule system not for GW's rules.
Wargs are based 2 per 50mm square Renedra bases with disorder & breakthrough markers on 40mm metal washers and unit spent / worn markers on 60mm MDF circles.
As with a lot of stuff these days it was relatively easy to pick up some used Fenrisian Wolves on ebay for a good price and just repaint them to my needs.