help with Epox 4g4a+ memory settings?

Hi. I hope someone can help me with memory settings and questions:
I'm about to receive an Epox EP-4G4A+ motherboard with award BIOS using P4 2.53GHz, and 512mb of DDR PC2700 either CL2 or CL2.5.
I've looked at a downloaded manual, and there are two different places in the BIOS where memory settings can be adjusted:
1- In the Frequency/voltage control section, memory frequency can be set to FSB, FSB*4/3, and AUTO.
2- Also, the Advanced chipset section offers DRAM timing selection of Normal, by SPD, and Turbo.

Gee, are these the same thing? If not, what's Normal and Turbo mean, exactly (not explained in the manual)?
I assume that FSB gives 2*133MHz for PC2100, AUTO will read the memory chips and set to PC2700, and FSB*4/3 will set to, um, ~354.5MHz with a 133/533MHz FSB. Does that sound right? If not, how do I select the "unofficial" support for DDR2700?
(gee, what if i bought PC3200 and wanted to clock it down to PC2700? seems like I couldn't do that)

If anyone has played with these settings and is familiar with them, your help would be appreciated.

PS - any advice on whether its worth buying CL2 memory instead of CL2.5 both at PC2700? I might try some light overclocking. Please see my question, "best DDR memory choice?" posted in "memory" section.
Thanks.

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