I have both 2x512 OCZ platinum Ed.Rev2 (TCCD) & 2x512 Geil One W (BH-5) and they are 2 types of different IC's. The Geil modules will need (in my case +3.5v to reach +250FSB), so It's going to be very hard, or better, just impossible to hit 300 1:1, but they will run 2-2-2-5 timmings up to 250 (even 1.5-2-2-5). On the Other hand, my OCZ modules went up to 330x8 1:1 (2.5-4-3-7)@2.7v or 310x9 1:1 (2.5-4-3-8)@2.7v or 300x9 1:1 (2.5-3-3-6)@2.6v
You have to decide wether you want Tight timmings + high DRAM voltage + lower FSB or Loose Timmings + low DRAM voltage + Higher FSB.
If you are going to OC and you have a CPU with high multi's (11 and up) I'd go with BH-5 type of memory, but If you have low multi's on your CPU I would grab some TCCD memory.
EDIT: Sorry, I thought you were talking about Geil One W not Geil One S.
I'll get Geil or OCZ if I were you.