Pooboys Products never disappoint. They are very noob-friendly, and the results are incredible. SG on the other hand can be a PITA to work with. Ive never worked with Jetseal but CG seem to put out really high quality stuff, but ive read they can be hit or miss (although JS seems to be a hit).
Id recommend EX-P topped with Nattys wax (Nattys Blue if youve got a dark colored car). This is actually what im currently using. EX-P goes on easily by hand or machine, and comes off even easier.
http://www.poorboysworld.com/exp.htm
http://www.poorboysworld.com/natty-blue.htm