Garret Wade or WoodCraft would be good places to start.
I've never been a fan of carborundum stones, far too coarse in even the finest grit and soft enough that they go hollow way too soon. Your mileage may vary.
The best overall utility stone I've ever had is the medium grit India stone. Man made, meant to be oil lubricated, hard enough to remain flat for eons and available in dozens of shapes and sizes. Cheap, too.
The best oilstone oil is good ol' pharmaceutical grade mineral oil from the drug store. Two buck's worth will last you and your descendents well into the twenty seventh century. All the stone manufacurers sell it under their own names for ten or so times what it will cost you at your friendly local Sav-On.
Also if you should get bound up, a pull on your stone oil bottle will have your inward workings free and running in short order, as well.
Stay away from the Japanese water stones, they are far too soft for utility work, it's like using chalk. Some of the ceramics are good. I've not had good luck with diamond embedded sharpening stones.
Three Hawks