A small investment in the right tools and you'll be a happy cable installer for life.
Far and away the best way to cut the cable housing is with this:
It's a Dremel diamond cutoff wheel. It costs about $12. It will cut the housing square and cleanly without buggering up the inner coating. After you cut the cable housing, use the flat part of the wheel to lightly polish and round off the edges.
Then, use these to cut the inner cable:
Those aren't just any old wire cutters. Those are Shimano cable cutters designed specifically to do a good job cutting the stranded stainless inner cables. They cost about $50, but they're worth every penny. Take care of them. Make sure the bolt holding the jaws together stays tight enough for the two halves to scissor past each other to cut the cable. Mine are actually a bit stiff to open and close, but they cut perfectly cleanly like that.
Get a bottle of brake cable ends and a bottle of derailleur cable ends.
They run about $12/bottle of 250 each at Nashbar. That's about a lifetime supply.
So, for a small investment in the proper tools, you'll be set for installing or repairing your own cables for life.