If you cant afford the GH4 Id suggest getting a GH3 or even a GH2
I currently have a GH2, that I patched to run at 150gbs instead of the in box 60gbs. At the patched rate in pulls 1G of data a minute. Crazy fast! I bought it about 5yrs ago and its still going strong.
I paid $150 US for a Rode Run and gun shotgun mic at B&H photovideo.com
As far as inexpensive and tested monitors, rigs, mics and tips to make your productions look professional check out the Flim Riot youtube channel