Hmmmm,.,, seeing as you are only 14yrs,,, and you have limited income,, I would say ,,, STICK WITH THE PC2100!
First ,, the more ram the better,, but moreso,,you will get a good "bang" for a lesser buck,, this is the problem with kids today,, always thinking that bigger and faster is better,,, not so!!
You only have a 256 of PC2100,, sure there is faster ram but wont you get improved performance by simply going to 512 or a Gig of PC2100?? YES of course you would,, and then you would still have some pocket money towards that video card too!!
You are pushing the limit of that board by going to the PC3200,, that is the MAX of what that board can handle,, and MSI has issues (in my opinion) of what they call a "working Max",,
Seriously,, you can have a GREAT running PC with punch and all with what you have,, add the 9800 pro,, get a GIG of PC2100 ram,,
PLUS..ever consider what the drag to your Power supply will be,, and does it provide enough juice to support what you WANT to get over what will WORK??
PC3200 takes a fair chunk of power,, and the 9800 will require good juice to support,, add in your drives, burners, etc,,etc,,
Next you will need a new case,,,
First Rule: K.I.S.S - Keep It Simple, Stupid