Well, crucial got its reputation because its pc2100 sticks are often capable of running in excess of pc2700 speeds. I don't know how well their pc2700 does.
If you plan on running them at 166mhz, then either of those should be fine, and will probably be capable of running at a lower latency, too.
On the other hand, if you plan on overclocking, or running the memory above 166mhz in any way, I would suggest pc3200. The best pc3200 is the Corsair XMS. I highly reccomend it anyways, because Barton AMD chips will come in a 200fsb version, and you'll need pc3200 or better to run with that if you upgrade.