My 2 penneth:
pedals
seatpost
seat
cranks
Do not spend money on a bolt kit until you've done that, and possibly changed the cassette. Besides which going all titanium on bolts is silly when in fact there are some low stress areas of a bike that could take lighter aluminium bolts instead of titanium (e.g. bottle cage bolts, shifter mount bolts, brake lever mount bolts.
I bet your cranks alone weigh about 1 kilo or over !
seatpost->
http://www.chainreactioncycles.com/Mode ... elID=11375
pedals->
http://www.chainreactioncycles.com/Mode ... elID=52884
or
http://www.chainreactioncycles.com/Mode ... elID=17264
saddle->
http://www.chainreactioncycles.com/Mode ... elID=58327
For cranks I'd keep an eye out for something second hand in the for sale section or hold out a spend a little more on something modern but light (e.g. deore 9 speed octalink cranks and bottom bracket).
If you don't need quick release wheels then replace your skewers with these:
http://www.chainreactioncycles.com/Mode ... elID=26621
Same goes for seat clamp e.g.
http://www.chainreactioncycles.com/Mode ... delID=6255
If you are feeling really cheap/poor I have an sdg saddle with a small chunk missing that I can send you for postage cost. A seat cover would hide the damage, or a leather patch could be glued on with shoe-goo or marathon/bison (from sports shops).