I recently became aware of a 6 foot JCP in dire need of new living conditions. The current owner, who I can tell loves him dearly, has been unable to provide proper living conditions and describes his current housing arrangement as "squished." I am assuming she did not realize he would grow that large and likely has him in a 30-40 gallon tank (poor guy

).
She no longer has the time to care for him and wants to get a smaller snake for reasons I will leave unmentioned.
Obviously I am torn, as I hate to hear/see snakes that have poor living conditions. Right now I am leaning towards adopting him, but am trying to figure out caging and spatial arrangements.
Apparently he has become slightly aggressive, due to lack of handling. Prior to this lapse in handling, she said that she'd take him in public with no problems whatsoever.
He is about 4 years old and
I am wondering if I will be able to get him to tolerate me with persistent, yet gentle handling, and by offering him a nice, spacious living arrangement? I think I am going to see him tomorrow, but I thought I'd ask the aforementioned question (even though I will likely adopt him as soon as I get him a cage in the next week or two!).
My girlfriend is a little wary, as this will be the largest snake she's ever been in contact with and does not want to get tagged by him. Sorry for the winded post and thanks in advance for your opinion!
BTW, he is very handsome--pictures will come as soon as possible...