Since I can't find a "SEARCH" button on the site I have to post this question.

I'm interested in putting a light on my M4gery which has a RAS II installed.  I like the setup of the M900A, but it seems pretty pricy.  So, my question is this:

If I don't use a M900A, what's my best option for a Front Grip / Under Barrel Light combo?  I like the "round" broomstick style grip, and want a 125 lumen light.  What's my best option?  

Since you specified you want 125 lumens, your only real option is Surefire. The Knights Armament Vertical grip or the new Duane Dieter grip should work well with one of surefire's 9 volt millenium lights...probably the M961 or M962. The Dieter grip appears to have a recess for the tape switch and cable,if you go that route,which will keep them from snagging.  I was in the same postion as you when I was deciding how to equip my SIR-M /M4. I knew I wanted a vert grip but also wanted the light at the 6 o'clock to keep smoke out of the light beam. I went with the M900a and have never regretted it, although it is a large chunk of dough to pay for a flashlight. Considering that a quality light, mount and foregrip comes close to $400, I decided that the M900 was not such a stretch after all.
Give Donnie at Sableco.net a call. He'll give you that best deal on whichever combo you decide on.

Initially, I had a separate RAS-mounted Surefire and Knights vertical grip.  Replaced it with the M900AB.  The M900AB kicks ass.  It is way more functional and "clean"--no exposed wires or pressure pads to mount.  If you can scrape together the cash, get the M900A--it's worth the cost IMO.

[img]http://www.printroom.com/_vti_bin/ViewImage.dll?userid=sharkman&album_id=102226&image_id=8&courtesy=1[/img]

I think I've convinced myself to buy the M900A when I have some extra cash.  I think it makes the most sense for a lot of reasons.

Slightly off topic but just something else to consider...the M900 is heavy and therefore makes the AR feel muzzle heavy like having an H-bar.  It takes more effort to overcome the initial inertia and more effort to stop, analogous to shorter barrel shotguns that are fast for snap shooting vs. the longer barreled ones which are slower but better for encouraging tracking and follow through.  

[b]"the M900 is heavy and therefore makes the AR feel muzzle heavy like having an H-bar"[/b]

as compared to what?

PPD,

Compared to a M4 profile.  I had a stock AR with a HBar that felt muzzle heavy, unbalanced.  When the barrel was turned down to an M4 configuration, it felt and swung better for me.  When I added the M900, it was like having HBar back on, destroying the balance achieved.  Otherwise, I liked everything else about the M900, especially its rock solid feel.

The M500 I had before made the rifle very front heavy.  Too bad they don't make a composite M900 instead.

Is the M900 any heavier than a Millenium universal light with a KAC front grip?  If so how much?  I found the M900 to be quite light for what it is.