Hello all. I am new to the forum. I know my username is random, but I'm mostly on car forums and couldn't come up with anything else. 

(If you don't care about my story, skip the the questions)
I have done as much research as I can so please don't bash me too hard. This is my first ever attempt at upgrading a computer. 
So my dad gave me the responsibility of giving my grandma's old computer just a little more kick. I used the re-install disc for xp and it is running much better but still somewhat slow. After talking to my dad some, he said he'd be willing to pay for a couple small hardware upgrades. After some research, I came to the conclusion that my best bet would be upgrading the RAM from 256mb to 1gb and going from the Celeron to a Pentium 4.

Questions
-Would I bet better getting x2 512mb sticks of ram or 1x 1 gb?
-Which exact products would you suggest? Or are all sticks of ram and all pentium 4's the same? I'm just scared I'm going to order the parts and I'm going to have missed something in the fine print.

I found these. Will they work?

[URL" target="_blank">http://www.ebay.com/itm/1GB-PC2700-DDR-MEMORY-Dell-Dimension-2400-4600-8300-/140588035735?pt=LH_DefaultDomain_0&hash=item20bbb3 2e97#ht_1039wt_952]PENTIUM 4 3.06 GHz ( SL6PG SL6S5 )(512K/533/ SOCKT 478) | eBay

http://www.ebay.com/itm/1GB-PC2700-D...#ht_1039wt_952

Thank for the help. I tried searching as much as I could.