Hi Robyn,
" I much prefer the variety I can get by starting seeds vs buying the sets available in local stores, my seed onions seem to grow so much bigger by harvest time. "
A third option is to select onion plants from Dixondale Farms.
https://www.dixondalefarms.com...
They have a good selection of varieties suitable for different locations, and will ship your selection at a time appropriate for in-ground planting in your area.
ZM (not associated with any product or vendor mentioned or linked)