I've seen a few other KLR people with the MRA spoiler with the MRA screen. To me the stock screen looks the same as the MRA screen but it's smoked. I could care less about the smoked screen and all I want is the spoiler.
Twisted Throttle sells just the spoiler but you have to make a template to figure out what dimension to buy. I'll save you some time and tell you if you have a 2008-2010 you need the VTA4 for your STOCK screen.
The Template is easy to make but you need a yard stick that that uses centimeters.
ADDED: Went for a 60+ mile ride down the highway and all I have to say is WOW, it's nice. Really wish I had this the from day one. I tried it all the way down and it was like it wasn't even on the bike. Then all the way up and it feels just like the Kawi tall screen but no annoying buffeting. This is really going to be perfect on the big great lakes tour I'm doing on the first week of June.!!