just thinking the one problem i had with sata was getting the cables on the site it doesnt say they are included and they cost about £5 for two. that was very annoying after the HD's arrived late lol, couldnt even plug them in.

your processor decision looks good but depending on your budget i would be tempted to go for the 3200+ the price difference being £15 - the 3200 being very responsive and i would definatley sya that increased my performance the most.

to be honest i know little about DDR2 but from what ive picked up its worth getting if you have the money. it takes less power than DDR does and it works at better speeds.
one thing i know for sure about memory is go for 2 smaller sitcks than one large stick eg 2*256 than 512 as the computer can write to each stick simultainously while one stick refreshes - no time is lost (contineous data flow). if only 1 stick is there is has to wait during this period the "idle time".