Originally Posted by Autumn
- singer, playing small, acoustically iffy venues like rock clubs & bars with a full band
- soprano range, probably in need of good mids (& treble that won't make me go deaf/stab my eardrums)
- good isolation/keep Autumn from making her tinnitus an indisputable reality
- custom not mandatory but would be nice (haven't fit customs before, any pointers also welcome)
I would recommend a single driver or dual driver custom IEM.
Why custom? It's an investment you'll find useful. Your ears will thank you for the comfort of using a CIEM after several hours performing live. The superior isolation (only Etymotic models isolate on par or better, but they're usually not as comfortable as their proponents say they are) will allow you to monitor at levels that won't cause long term NIHL (<85 dBA, per OSHA/NIOSH recommendations). As comfortable as the Shure and Westone style earphones are, they really don't provide as much isolation as you'll actually want when you're performing day in and day out. I would recommend something like the InEar StageDiver SD2, which is universal-fit but very isolating, but it's a little out of your budget. The SD1 fits your budget, but I don't really recommend it on the basis of sound quality, which I find wanting.
As you're a vocalist, you need accurate monitoring of vocals. Usually single driver models and dual driiver models (such as the 1723 AcuPass models) will do well in this regard, because single driver models are relatively immune to phase issues, giving you a more accurate lay of the land when your monitor engineer is giving you what he's picking up on the instruments and from the ambient microphones. Single driver models won't give you the "body", "richness", and "texture" of something more upmarket, but they'll do the job just fine. You're using them mostly for work, not for fanatical audiophile pursuit. An AcuPass dual driver is also fairly immune to most phase issues as well.
For silicone, your best bet would be to go with CustomArt. Peter's Music One is very good --- very natural and very resolving, with just the right amount of mid focus to give you the upfront visualization of vocal fundamentals that you might need to hit your notes at just the right rhythm and cadence. Overall, it's got a response that's just warm of neutral, so you'll get a great lay of the land. Both Joker and Average_Joe reviewed it (and rated it highly); and I'm in the process of reviewing it (previously, I reviewed the Pro100, but I find the Music One to be better for more purposes).
For acrylic, while I don't have experience with the brand at all, the new Perfect-Seal Laboratories looks promising. Its SportBud line looks affordable and it's less obtrusive looking because it uses an ITC design (read: smaller shell) rather than the traditional ITE design. In addition, it uses heat-reactive resin for the canal tips just like Westone's Elite Series, making it more comfortable.
I'm trying to recommend things <$300, because an audiologist's visit will run you anywhere from $30-$100. Add in options that you may want, such as aesthetic stuff, and you might be pushing $400.