So my wife(bless her heart) picked me up a M&P Sport model for X-Mas. In fact she grabbed 2 of them on sale just a few days before the madness started. My first thought is to break one down and re-build it to make it mid length and add the FA and DC. Is this reasonable and what's the best way to go about it? Do I just try getting a whole new upper and slap it on or what? Keep in mind I'm not rich and cost is a factor.