maddogfargo :
Have you considered using an EK or AlphaCool kit? They perform great, are complete and competitivelty priced, and include Compression fittings.
i would also suggest this. the kits are all the same parts you would normally buy seperately, but often at quite a lower price than buying piecemeal. they also come with all the things you need to build a simple loop, usually including either compression fittings, or clamps with barb fittings.
as for clamps alone, yes. use them. i've seen people say they never used them and never had a problem, but how much will some clamps cost? compared to replacing a soaked gpu or worse? better safe than sorry.