Don't bother avoiding the Yikes! G4 -- it's a great system. My blue-and-white G3 came with a Yikes board and over the years, I never had any major troubles with it. I use a G3 G3@450/1M CPU in it and it was always a great performer both with Mac OS 9 and with OS X 10.3/10.4.
I don't remember the Yikes being on the Road Apple list, but it's one of those situations where LEM got the mark way wrong, or had it right only so extremely briefly that in retrospect it's laughable they bothered at all.
You probably would have wanted to avoid buying one new, but if you could get one used in the era where sawtooth was still relevant anyway, then it wasn't a huge difference unless you were planning on totally hotrodding the sawtooth. The Yikes has, because of reasons that are obvious, the same limitations as a blue-and-white G3 in terms of upgrades, but sawtooth can take newer video cards and CPUs.
That said: Today if that's what you're looking to do, you should probably start with a digital audio, quicksilver, or mirrored drive door. dA/QS would probably be the best choice if you're looking to get into OS 9 specifically.
The Power Macintosh G3 and G4 series are each relatively short lived, but there's a lot of variety in tere so it depends on what stuff you want to do, if you're searching for something specific. If you just want "something" then there's no real great reason to avoid any of the G4s, or even most of the G3s, if you're comfortable installing some kind of expansion card if you happen to get a blue-and-white Rev 1 and you need to run more than one internal hard disk, which was what the problem with the disk controller was, it was errors handling two hard disks and otherwise you can use one with no real trouble, as my understanding goes.
