Is there any reason you don't want to go with an L4/E2E/E2D and Vltor mount combo?
I really like the concept of the Scout Light but after doing some research and finding out that other than the integrated mount the Scout Light is exactly the same as the E series lights I found it difficult to justify it's extra cost.
I would have thought the Scout Light would at least have a machined battery stop for the $$ it costs.
Also, any of the tailcaps, lamp heads and bezel adapters that the Scout Light has can also be used on the E series lights.
The L4/E2E/E2D and Vltor mount will get you the same thing as the Scout Light and save you a lot of $$.
The only real advantage I can see for the Scout Light is the offset mount it can be ordered with. Again, this may or may not be worth the extra cost depending on your needs.