Online Directed Dealers

None that I know of.  If you don't have a local directed dealer, contact them and see if they'll sell you gear directly (no pun intended).

So if I buy it off the internet and have a dealership install it, is it still covered under the lifetime warrenty.

I'm going to say no to this one.  Directed would have to make the call, but if you purchased it online, and there are no online authorized dealers you would not know the condition of the equipment you recieved- used, refurb, etc (cleverly repackaged and sold as new).  That's the position I'd see Directed taking, and they have every right to. 

See if a local shop can get it for you.  If not, get on the phone and call the closest Directed dealer near you.  Set up an appointment, and make the long drive out there.  If that doesn't seem like a workable option, see if they'll come to you- some places have vans they send installers out in- it'll cost you, but it's worth it to keep the warranty.