Syd, I really like the preamps in Sound Devices, but if your budget is so limited, In wireless I think the Sennheisers G2 could be a good investment, I don't have the models here, but you must have the package that includes lapel omnidirectional (me2) robust and good sound. And ntg2 RODE shotgun (works with one AA). ambiences can be made directly with the D50 mic, they sound really good, highly recommended!
Hope this helps!
Erick del Valle
Santiago de Chile