Some of the knowledgeable folks on this website suggest the one from Mini circuits. I have had good luck with an inexpensive rockwell/collins unit I got on ebay for cheap. I would not be surprised of the mini circuits model has better specs. Also only use the filter if you have too, any filter may have loss. If you don't see the wideband FM radio emissions on your scope when you crank up the gain, you may not need the filter.
Not exactly. My understanding is that Airspy can be used remotely, but its not a web interface. You run a server program on the computer connected to the airspy, and the remote computer connects via airspy itself. So you use the airspy program remotely with the help of a local server program, but its not a web interface. If you download a copy of airspy that is current, you will see the option to connect to other peoples airspys on the internet. So that's a good way to trial it.
I would add that you may do just as well with the airspy MINI for less cost. I have one as well and am pleased.