Tyre weight make s alot of difference purely because rotating weight ( when moving ) is greater than static weight.
Rear tyre for me would be try-all stiky light if you ride smoothly and can afford it.
If your a bit heavier or land heavily then Der Kaiser / Rain King ( conti )
If you want a light tyre but cant afford the try-all lite and dont mind sacrificing a bit of grip try the Kenda Nevegal 2.5 stik-e single ply.
If you want a tyre that can take some shit, maxxis Minion 2.5 stiky 42a, slightly less grippy and long lasting as a Der Kaiser / Baron / RAin KIng
You should notice a fair increase in grip ( and, depending on tyre choice ) puncture resistance.