here's a link to an article that gives more information on the flu shot.
http://www.cdc.gov/FLU/about/qa/nasalspray.htm
I do believe I've also read up that people at high risk should not get the live vaccine, as it has not been proven to be safe for them. I would certainly try to get the shot over the nasal spray.
The H1N1 shot though does make your arm much more sore then dose the regular seasonal flu shot.