Ok as for your heatercore, as long as the damage isnt extensive to cause leaks it should be ok... you could straighten out the fins. Not a biggie. And you do not need to put on new babrs as you can boil the tube and shove over it. Some people cut the barb shorter and some people dont...
Since you are tight on money....
CPU: Maze 4
Pump: Mag 3
fill/bleed: t-line (home depot)
tubing: home depot 1/2ID, 1/8"thickness and test it to see it does not kink, teflon tape might be nice, metal clamps
edit - on the second thought... go with SwiftyMCW5002 a lil bit more but lot better