which would be better? PC3000 /PC3200 BH-5 chips or PC3500 CH-5 chips?

title asks it all!

BH5. It'll run tighter timings and accepts higher voltages better than the CH5.

~THT

BH-5 = better fo overclocking

unfortuenately the original question was not answered,i know what BH5 and CH5 are...

As a direct answer, get PC3000 or PC3200, unless you can find PC3500 with BH5 chips.

Speed Rating advertising means little, except that if the memory doesn't reach the clock speed at said timing (usually loose) you can RMA it. But it doesn't mean jack about overclocking ect. The most important thing in memory (besides issues with assembler) is the memory chip. If one chip is better then another, then it doesn't matter what advertising rating is given to it the worser chip, it's still worser.