help with problems new to this car

[plati13]

i have an 1987 supra turbo 5 speed
ok well first thing is is i hear a clicking noise when reved not at idle and then it also vibrates when reved not at idle and the vibration with happen when you go to take off and it dogs down when driving it has no balls at all, and then on the highway the only way the boost is on is when my foot is on the pedal for about ten seconds then it comes on to about 1 psi if that maybe a half and i have a valve cover leak and wondering about how long and how much of a pain will it be to do it and how much it will cost

and i thank you for any help given