edge pro stones are 1 inch wide and 6 inches long...and welcome to the forums. as far as good aftermarket stones there are atomas 140, 400, 600, 1200; shapton glass stones from 220 to 30k, very many nubatamas in various grits and grades--bamboo or gold for example-- those are the best ones IMO.
you may have luck with an atoma to start (140 or 400 depending on how much steel you wish to remove) then a shapton glass 500, 1000, 4000, 6000 and maybe an 8k. I use that very progression followed by a 1 micron diamond paste leather strop and I like the results.
if you like a toothier edge you could use only atomas followed by a light stropping.
there are a lot of good options. it all depends on what your knife will be cutting the most of.