I'm considering putting together a panel show, and for that, I need 5 lavalier microphones.

I had been using Giant Squid mics with field recorders such as the Zoom H2n and Zoom H4n, but there are two problems - first, it's difficult to monitor the levels while recording, as you don't know until you get back in the editing room if you have the audio you want. Second, it costs money for a field recorder for each person, and the more field recorders, the more points of failure.

I already have a Juicedlink adaptor, so I've got two inputs into the camera. But what I'd like to do is get a mixer for five or more audio inputs.

Here's the difficulty: Cameras and field recorders have mic-in inputs which provide a little bit of phantom power, so you can just plug in an unpowered Giant Squid mic and roll with it. But mixers have line-in - which provides no power.

I could use something like the ATR-3350 as a lav mic with an external battery, but the problem with those microphones is that they have 20 feet of unshielded cable, and interference is a huge concern of mine with those microphones.

What would you recommend for an audio solution for mixing 5+ lav mics? I'm willing to invest in buying a new microphone and investing in a mixer, but whatever it is needs to work reliably.

Organize a mixing console and an operator that knows what they are doing..... get it done right the first time, it will save you hours of unnecessary work in post production.....

When are people going to realise that if there are more mics needed than the number of tracks to iso record on you need an sound operator. SIMPLE
And if the response is "we haven't got the budget for it" !!!! Well then you shouldn't do the shoot.

Sorry for my blunt reply but people shooting short handed and delivering a rubbish product is only giving the entire industry a bad rap.

Sounds like a Tescam DR-680 would fit your needs. Can monitor the audio levels from one place, and record them all separately.

Tascam DR-680 8-Track Portable Field Audio Recorder DR-680 B&H

I'll second the dr680. Its got some limitations, but you can provide power to 6 mics, record them, and adjust a mix for monitoring or to simultaneously record to a stereo track.

The downside? The headphone amp on the dr680 is complete crap. If you turn it up loud enough to monitor, it hisses like a snake. However, i've found it workable as you can still monitor and adjust levels well enough to get good recordings, and the recordings are very clean.

There are much better solutions, but nothing else in that price range. Its a gem for the money.

A multi-track recorder is the best option. Another option is an auto-mixer like the Shure 810, however they ain't fool-proof and must be set-up properly. (as does everything else regardless) If the project is mixed on the fly, this should be done by an experienced operator, preferably on a console with linear faders. If the mixer doesn't have a direct site-line, multi-cam monitors are almost a necessity. Mixing roundtable and panel discussions is a different skill-set all together and is loaded with pitfalls.

As a cheap solution, check out the Zoom R16. It can record 8 simultaneous tracks to SD cards and it can be powered by batteries if needed. Weighs about the same as a first gen iPad.
I bought one for a shoot I did with 6 actors all with speaking parts and it worked great! And I second the statement, if you have to mix on the fly, hire an experienced pro. I am an experienced pro with audio but I wanted to wear my camera op hat on that particular shoot. Made life easy as once levels are set, just start recording and forget about it.
http://www.zzounds.com/item--ZOMR16

Sound op with proper mixer, connected to a multitrack, or computer D/A and hard disk recording. Lavs can be cable if they are seated and not going to move - so hire in some with XLRs will be best. Sound op is essential - totally agree with the statement higher up. If you are doing a panel show, you need a sound op anyway to play in the effects, sig music, and maybe even audience? Far to complex for the cameramen to cope with. With multiple people, you'll be doing re-shoots and lots of edits - so a floor manager to keep control and also to keep track of what is going on is essential. We used to recon 2 hours to do 30 minutes was good going!