Thanks for the comments, guys!
Getting aftermarket parts for this truck was a PAIN. I had do to a lot of research, so I'll break it down for you. I ordered all the parts from the local MidWest Truck Accessories (http://www.midwesttruckacc.com) here in Michigan.
Headlight Covers:
Auto Ventshade 2006 Ford Explorer (Model# 37458)
Ventvisors In-Channel Deflectors:
Auto Ventshade 2007 Ford Explorer Sport Trac (Model# 194819)
Hood Shield:
Driver Design 2006 Ford Explorer (Model# 02251)
Basically, the whole front end of the 2007 Sport Trac is the same as a 2006 Ford Explorer. The only thing that I have not been able to find (and to my knowledge doesn't exist yet) is the tailight covers.