I'd tack up "Tire Kingdom" as a place to never go to again.
Napa replacements are like $30 each for the cheap, made in china, guaranteed not to last longer than how long it takes you to drive it out of the parking lot.
You can get the MOOG (what you want) pitman and idler arm for ~$200 from numerous vendors. I searched around the internet and snatched up a set for $140. Or your local parts store should have it for around $280
Replacing the idler arm support is highly recommended (one of those "while I'm in there" things). A MOOG iddler support is ~$70 from vendors, ~$50 if you search around. Or you can get a beefy aftermarket one for $200.
Labor should be 2 hours. It honestly is not very hard to do for a DIY.
2007.5 2500HD CC/SB LTZ
498 rwhp, 845 rwtq
DiamondEye 4", EFI Live by BobO, Edge Insight CTS, S&B Intake, Bilstein 5100 shocks, MOOG idler/pitman with SS support, Raptor 150, P553207, !PCV, !EGR, Transgo Jr, Rare Parts tie rods, 55 watt 4.5k HID low/hi/fogs, Belltech 3" lowering shackle