SSD is much faster, besides next year prices of SSD will be
super low.
For storage, a USB hard disk will suffice.(Two permenant
internal disk drive uses more power)
Anyway, its up to him to decide.
*facepalm.
Assuming he doesn't do storage? I can personally tell you that
40GB isn't enough for your main drive, especially if you intend to
play games.
My games folder itself is 60GB+, after uninstalling games I no
longer play. A Windows installation takes up 20GB. Rather than rely
on a USB harddrive, why not go for energy efficient HDDs? The price
of a 2TB WD Green drive is the same as the X25V.
For basic machines, an SSD is overkill.
Here's my take on a budget gaming PC. Balance between cost and
power.
Motherboard + CPU: AMD Athlon X4 640 + Biostar TA890FXE $332
RAM
Kingston 2x2GB 1333MHz $96
Hard Drive
Samsung 1.5TB 7200rpm $99
Graphics Card
Powercolor HD5770 1GB $205
Power Supply
Seasonic M12II 520W - $119
Optical Drive
LG DVD Super Multi $35
Casing NZXT Beta Evo - $83
Total Cost: $969
Optional upgrade: Add a Cooler Master Hyper 212+ (CPU Cooler)
for $59 if you want less noise and better cooling.
Each part chosen has it's purpose and a reason why I chose
it.