Question, someone was telling me that you have to get permission from the airport to monitor the freqs....that true?
I believe that someone was referring to UK regulations as Lezam stated.
Also, can someone still answer my question, how well with a 2 m jpole will a sporties handheld radio put out, and how will the quality be
Are you referring to a 2 meter copper J-pole? ...or a simple roll-up J-pole?
I don't see the purpose of using a copper J-pole with a handheld unless you use that handheld like a base station. I can't imagine a person sitting at the airport with a sporty's handheld leaning on his ~70cm long copper J-pole (roughly 2.25 feet) antenna, but I'm not saying you can't (although I'd like to see the picture

)
It is very dependant on the transmitters, their power output, surrounding terrain, and distance from the transmitter. VHF is line-of-sight, so pilots (being in the sky; above you) shouldn't be hard to receive in most cases, but ATC facility's low-power transmitters that are either obscured by terrain or are low-power transmitters will make it difficult to receive the controller side of the converstation.
Please clarify on which J-pole you're referring to and possibly including the purpose/use that you're trying to achieve (ie: Listening from home, at the airport, etc, etc) so we can answer your question(s) further.

Jason