Unless you are going to joint things much larger than guitar components, don't fixate on a 7 or 8. My favorite jointer for the stuff we see is a Stanley Bedrock 606 "flatside. Mine is completely "renewed" but is not perfectly flat. I am a bit of a heathen because I will say, "That is flat enough." Regular 6's usually go for less, a bit the influence of a Stanley expert(and he, Patrick Leach, is expert.) Google "Blood and Gore." Also, Stanley may be the most famous name in vintage quality planes but there are other smaller scale brands that are just as good. I have a mix of Bedrocks,Stanley/Bailey, Millers Falls, and a small variety of Lie Nielsen and Veritas planes. I'll add the photo of many of my planes that I frequently have shown when handplanes come up. Not shown is a Bedrock 608 Flatside that I have-not renewed but with aftermarket blade and capiron that I have not needed. It was not a cheap acquisition, even though it is not pretty-everything that matters is there.
I have been doing very good honing of a variety of blades since I was 7 or 8.I was taught to use a plane properly at about the same time. I never quite lost touch with that heritage even at the present power tool level I have.
Let me throw this out to you as gospel-A properly setup and sharpened plane can control cuts to .002 inch--two-thousanths of an inch. I have a couple setup to .001 cuts.