I have one of those squeeze lock things too. They're good enough and they'll fit the mounting grommets on the BCD. I haven't used a trilobite but I saw a pretty convincing video about it the other day and it's on my list of things I want for Christmas.
What ever you do don't spend a whole bunch of money on a dive knife. If you haven't been diving for long you'll soon learn that if you do lose something during a dive it will be your knife.
Also, don't forget to spread a layer of Vaseline on the blade before you go diving with it, even if it says it's stainless steel. Not all SS is created equal and keeping water from directly contacting the metal will significantly extend the life of the blade.
R..,