1998xjspt

my brake booster has a leak in it which makes it squeal when i apply a certain amount of pressure to the brakes. once the day goes on and the truck heats up the noise goes away which i don't know why but anyways.. if i go on to replace my break booster, is there a better one in another model XJ or ZJ that i can get which will preform better? or anything that can stop the leak??

don't know much about break boosters and master cylinders so any help is appreciated.