1993 Mitsubishi 3000GT Clutch or Transmission

I have a 1993 3000GT VR4, Twin-turbo V-6 with a 5-speed Getrag that is having some issues. Some people are saying I can get by with just a clutch job others are saying I require a transmission rebuild. It is pretty much hit or miss weither or not the car goes into 3rd or 4th anymore while it's being driven but if I am stopped I can get the transmission to shift but it has to grind pretty hard to get into 3rd or 4th. If it does go into either gear while driving it grinds extremely hard and occasionally feels like it doesn't go all the way into gear. Also, reverse grinds and kicks out of gear when I try to shift into it and I have to wait a second then slam the shifter into reverse to get it to catch.