mobile me 5gb

i have an opportunity to buy the 5gb from my friend for $20usd, im assuming he bought a family pack and is selling the left overs. I have the trial version now if i bought the 5gb would i be able to use the 5gb code to update my trial version to and would the 5gb be suffice for my needs as i only use the trial version account as a fwd for my school account to check. I dont really need all the other junk it does, so would this be ok for me to do?

so would i be able to use the mail application to get my school mail on my mac than?

never mind i set it up