NAPA should have of those parts in stock. They are very common. The bearings are Consolidated, and are pretty good quality. Chicago Rawhide is now owned by SKF, and are a quality part.
15141 and 15142 have the same dimensions. 15141 is a single lip seal design, the 15142 has a double lip to help prevent dirt from getting in the seal.
2000 Trans Am Convertible LPM A4 FAST 92 | Edelbrock Victor 90MM TB | Bosch 36# Injectors | Holley EFI Fuel Rails | GM 85MM MAF | FTP 98MM Clear Lid | Tick SNS Stage 2 Cam | BTR .660 Lift Springs | Trickflow PR | SLP 25% UDP | Pacesetter 1 3/4 LT's | 3" Exhaust | NGK TR55 | MSD Red Wires | Yank SS3600 Stall | Strange S60 | Strange Chromoly Steel Driveshaft | 3.54 Gears