If I may add my 2 cents, Though I like the look of a suppressor under the rail. There are some down sides to it. For instance, You CANNOT shoot the rifle unsuppressed. The gas and pressure and ruin your rail if you tried, and possibly hold your hand incorrectly and burn yourself. Also the heat may transfer to your rail a little quicker considering how hot a suppressor gets from shooting (I've melted quite a few things by laying my suppressor on it after a day of shooting). With the right suppressor and hand guard combo, you can get a "flush" look which may alleviate some of those issue, and also opens your options on suppressors and mounts.
I didnt consider that. I will now though....ahhhh! So many variables! But hey, thats what makes all of this fun.