for the bag, check out the powerbook forum - there's a sticky thread with about eight billion posts of recommendations. should be one there that does the trick.
for memory, do a search in this forum as this has been discussed quite a bit. i can't remember who people recommend but it should be easy to find. i must have been feeling wealthy cos i got an apple stick installed when i bought my 'book, so i'm not much help. just be careful that you get decent quality stuff as cheap ram seems to cause loads of problems.
sminch