PC2100 vs PC2700 Toshiba Laptop Computer

[coolguy2008]

I currently have a A45-S120 Toshiba Satellite laptop computer, with
256MB of PC2100 266 Mhz Ram, and a
Celron 2.6 Ghz Processor,
I believe the FSB is 400 Mhz
I want to upgrade the Ram. I am running Windows XP home addition.
It has only 2 Ram slots, I intend to buy 1GB of Ram
1) Does PC2700 333Mhz make much of a difference over PC2100 266Mhz?
Based on 333 vs 266, I would assume it to be 25% faster like 125% vs 100%, is that right?
2) Since my 256Ram is at PC2100 266Mhz, the PC 2700 would only run at 266Mhz. Which is better, 1GB of PC2700 333Mhz Ram, or 1.256GB of PC2100 266Mhz Ram?

3) Do they make PC3200 400Mhz Ram for laptops like this? Since apparently the FSB is 400Mhz. This is an example of the Ram I am considering:
https://www.memory-up.com/memory_Fin...=3628&system=1

[osprey4]

Hi coolguy2008,

Crucial recommends this, PC2700, up to 1GB per slot.

My suggestion would be to buy this used, since it will be much cheaper for name-brand quality.