Mustang Boards - SLP's Loudmouth 1's & Power-Flo Exhaust

Good morning everyone.
I just recently bought and installed the SLP LM1's from MT.com, for my 05 GT. While I love the sound and volume of them, this weekend while me, my wife, and our 18 month old son were running around doing some errands, she made several comments about the interior volume level from them.

While I personally like it, she did make a point that I hadn't really thought of and seemed pretty valid; She said that what if it's too loud for him at his age? That got me kind of worried and thinking. What she was really refering to, wasn't the exhaust noise perse, (I'm meaning the sound you would hear if you were outside the car and hearing the "Harley-Davidson" sound), whe was talking about that kind of "hum" (sorry, I can't exactly/accurately describe it) that you get when you're inside the car, and seems to be amplified when the windows are up, as they were when we were out.

So, what I wanted to find out was a couple of things. As for the volume, would the Power-Flo's from SLP be significantly lower in volume? Knowing that I know what the LM1's sound like, could someone give me an idea of what the Power-Flo's sound like in comparrison?

As for installing the Power-Flo's, can the section of pipe that connects the Loudmouths themselves to the mid-pipe, also be used for the Power-Flo's? If so, does MT.com sell just the Power-Flows wihtout that connecting piece of pipe and if so for that, would it be cheaper than buying the Power-Flo's and connecting pipe that's currently listed on MT.com's site?