chibear wrote:16GB is probably the minimum these days for music production.
Disagree. I'm working on a mere 4GB and doing fine, though I'm not using much in the way of VSTs. Even with that unless you're really going heavy on them, 8GB is probably fine for most. That said, memory is cheap, so I would probably buy a 4GB or 8GB RAM system and upgrade to 16.
I would not build one, unless you just enjoy the process. You won't save much money. Re. hard drives, basically none are 5400 any more, so not a concern.
Re processor, my comments on RAM apply here...sure more is better but there are so many variations or "models" now that the diff between an i3/i5/i7 vary a LOT and aren't necessarily much. Sure get as much as you can but people have to consider budgets too.