you pretty much need to use the HD component output, (Y/Pb/Pr), from the camera. The Panasonic LH1700 would be my first choice by a mile, in fact I plan to rent one for our next project in about a month. It can run on batteries and also has a built in wave form monitor to check exposure, but they are around $2800 to purchase. I have also used the LH900, but I don’t consider it large enough to set focus, although others may disagree. Budget is always a big issue for us as well, so on the cheaper side of things we use Keydigital Component to VGA converters to drive LCD computer monitors. We currently have two paired up with Envision 19″ 1440 X 900 wide screen monitors, ($325 for the converter and $200 for the monitors at Costco). The down side of this is they only work in the 720P modes, the colors are a little off, the image is a little soft and just not as pretty as what the camera is producing, so I would NOT use this method for judging color or exposure, but I do think it’s adequate for focusing. By the way, one of my preferred setups is to put the good monitor, (like the LH1700) at the camera for the DP to use, (that would me), and set the cheapo monitors out for the director, clients and other on lookers to see composition/action, (and to keep them away from the real monitor). Only other issue is the cheapo system does not seem to work when playing clips back from the camera so you may need to review from your NLE or the P2 player on a computer.
https://catalog2.panasonic.com/webapp/wcs/stores/servlet/ModelList?storeId=11201&catalogId=13051&catGroupId=14625