I'm going to bite the bullet after reading multiple articles and threads on using ECC RAM. Seems there are limited choices however as follows.
My my applicable main build components are:
Asus TUF GAMING X570-PLUS (WI-FI) ATX AM4 Motherboard
AMD Ryzen 5 5600X 3.7 GHz 6-Core Processor
Based on this article I assume that I should avoid UDIMM and SODIMM, but go for either RDIMM or LRDIMM?
DIMM Types: UDIMM vs. RDIMM vs. LRDIMM
The main brands appear to be: Corsair, Crucial, Crucial by Micron (?), Micron, Kingston, PYN, Nemix, T-Force, V-Color and Patriot.
After searching Amazon, Best Buy, Newegg, B&H, MemoryC, Adorama as well as the manufacturers sites the only options I've found and that I assume are compatible with my hardware are:
32GB 2x16GB DDR4-3200 PC4-25600 2Rx8 RDIMM ECC Registered Memory by NEMIX RAM
Kingston DDR4 3200MT/s* ECC Registered DIMM
Kingston DDR4 3200MT/s* ECC Registered VLP DIMM
Crucial 32GB DDR4 3200 (PC4-25600) RDIMM CL22 Server Memory Module
Micron 16GB DDR4-3200 RDIMM 2Rx8 CL22 MTA18ASF2G72PDZ-3G2R
The two Kingston page links have so many options on each I have no idea how to begin choosing.