Although i do audio professionally, i don't have much experience with wireless. The usual i encounter are always AKG or Shure, but there's not much i can say about anything else. So i suggest you look through Mix magazine and see if you can get something good out of it : http://www.mixonline.com/Results/?cx=012233305324114920625%3Abogz03jxqpi&cof=FORID%3A11&ie=UTF-8&q=uhf&sa=Search&siteurl=mixonline.com%2F&ref= http://www.mixonline.com/Results/?cx=012233305324114920625%3Abogz03jxqpi&cof=FORID%3A11&ie=UTF-8&q=lavalier&sa=Search&siteurl=mixonline.com%252F&ref= If you want the best lav mics, look at DPA. Their mics have the most natural sound of all mics i know and are very popular despite being quite expensive. That said, there's a good chance you can get 95% of DPA's quality with some chinese shit that will last only a few years. Hard to tell really in the current market. Cheap mics can sound really excellent, but you need good specimen.

Sound proofing doesn't have to be expensive. If you don't mind how it looks you can take cheap insulation or curtains. You don't need expensive and heavy bass traps for speech.

If you have any questions, i'm sure a lot of folks here can give you some great help. I don't record much on location, so i can only tell you about studio work, should you need that info. I don't even know how to hide a lav, should you need to do that.

@Oedipax I appreciate you realizing that sound is as, if not more, important than video in most cases. From what you're saying about echo problems, I don't think you need sound-proofing, i think you need sound treatment, or acoustic treatment, as the kids may say these days :).

If you're in a definite area that you own or whatever and are set for good, then fiberglass can be great. You may want to make panels using 703 or 705 fiberglass, and you can cover them with cloth, etc. and place them as needed. A more short term fix could be putting sound blankets (furny pads) on the reflect floor – especially if you're booming overhead. I guess any reflective surfaces you cover – the better.

And finally, check your mics pickup pattern. If you're in a tight interior – a shotgun may not be the best option, have you tried a supercardioid or hypercardioid?

+1 For Sennheiser wireless systems. One of my contacts at the company has done some rather impressive demonstrations for me personally of the systems over the years, so I feel good about suggesting them even though I do not really have much experience using them.

if you have budget and leeway (some refuse headsets) for countrymen, yeah totally the best bet fgreat audio, as for TX/RX Sennheiser or Shure make good stuff even their, low budget stuff is good, I consistently use a $350 Shure wireless lav setup on shoots and and live events and it never fails me. Wireless is a huge pain in the rear end.. to get quality at a decent price.. I prefer a wire.. but in the event it can't happen I use Shure or Senn. systems, even their budget systems preform well.

Thanks for all the advice! We've had Sennheiser wireless lavs before and always had problems with the connectors wearing out and getting dropouts depending on slight changes in position, very frustrating. But maybe we got a bad set and shouldn't write them off totally. Definitely don't mind spending less than $3k if we can get a good workable solution.

Have you thought about using a zoom H4n portable recorder and use pluraleyes to sync in post`?