I've always liked the 2206. Recently I designed it into something and bought a dozen or so from a reputable outfit. The new chips do not work like the old ones and will not work correctly in many circuits. Specifically, they won't sweep, or even oscillate to spec, over the full supply range. You need to limit the supply voltage. IMO, these things are history and you need to use something else. The 8038 is even less available, probably too expensive, and has no business in any modern anything. It was a great part in its day, but it's day is long gone. My very first function generator was the SWTPc unit back in the '70s that was 8038 based.