Auto metal direct or Tabco.
They're all pretty Similar for the patch pieces. The full panels, doors and hoods are where you start seeing a big difference.
For example, my passenger side inner wheel well is from Tabco and the driver side was from LMC. Tabco ran out of stock by the time I started driver side. So I just ordered LMC which stocks any brand they can get a hold of.
The Tabco one is stamped a littler beefier and is more stiff. The LMC one worked fine but is noticeably less stiff, once on the truck there is little difference.
Price difference for that part was about $20
Body crossmember support pieces from Tabco were noticeably thicker then the LMC versions. Which means they will last longer when rust gets them again.