Affiliate Marketing Secrets

I want to upgrade my brother’s pc and he has the Kingston / KVR667D2N5/1G in his pc. Same as the one on this link.
http://www.misco.co.uk/product/Q65362?affiliate=ram&gclid=CMffj8Ka2LMCFe7MtAodZggAKA
My question is, if I want to upgrade the ram, can I use the 2gb like this link http://www.misco.co.uk/Product/Q128088/Kingston-ValueRam-2GB-PC6400-DDR2-RAM or http://www.misco.co.uk/Product/Q74932/Kingston-ValueRam-2GB-PC5300-DDR2-RAM
The 2gb ones on the link, are there difference with them both? or not?
What would you suggest?

I just turned 18 at the beginning of this month and this will be my first time ordering my own new cell phone. I have a Droid now but I am getting an early upgrade and will be paying 20$ (I have Verizon) to get a free Blackberry Curve (it was pre-owned. Not refurbished though).
My question is, what does it mean when, on the phone’s page, it says “Phone Requires Data Package”?
It brings me to a page when I click on the link and it says this:
Monthly Data Allowance, Monthly Access Fee, Rate After Allowance
Pay Per Use – $0.00 – $1.99 per 1MB
(Basic Phones Only)
.
75MB3 – $10.00 – $10.00 per 75MB
(Basic Phones Only)
.
2GB2 – $30.00 – $10.00 per 1GB
.
5GB – $50.00 – $10.00 per 1GB
.
10GB – $80.00 – $10.00 per 1GB
.
So if I payed 30$ for 2GB what exactly does that mean? And would it charge me 30$ every month after that or would it charge me only 10$ every month?
Please help me out!
Thankyou to those that answer.