umm...two very different questions there...
If you would like to make a knife, start with this
site. There are lot's of sites out there, this one happens to have some very good sensible tutorials.
If you want a custom made to order knife, I can put you in touch with some makers, but figure out your budget first. For a good maker to produce a made to order custom knife, you are usually going to have a starting price of between $500 - $700. If you want something really fancy, move that price up accordingly.
--Wintermute