I have a set of three DMT diamond "stones", each 6" long. I prefer the larger ones, but I got by with the 6" stones for years. (This
is the set.) You could also go with the DMT fine/extra-fine DuoSharp stone, which seems to be about $75 with the holder, and use sandpaper if you need to do some really coarse grinding. That will be cheaper in the short run, since you're unlikely to need to do any coarse work right away, and is likely what I would do if I were starting over with my current knowledge.
Learning to sharpen without a honing guide takes some practice, but it's not actually all that hard. I have an Eclipse-style guide, but I almost never use it unless I need to do a lot of grinding to reshape an edge.
I've got one of the older Wood River chisel sets, and it's fine. I wish they held their edge longer, but that's partly because I'm using a lower bevel angle than is standard. (The reasoning for that is, basically, I screwed up. I could re-grind them, but I'm used to it now.) I don't regret the purchase at all, since they've served me well for close to a decade.