Let me try to clear some things up. The old mac book pros were partially aluminum, but when they say aluminum on the site they mean the new Unibodied Aluminum macbooks. Theyre made out of a single cut piece of aluminum and are extremely durable.
I dunno if its what you need but for me I think theyre amazing. My girlfriend has the non pro aluminum macbook and its awesome.
I liked it enough that Im saving for an aluminum version as an upgrade to my current white intel macbook. Just make sure you get a pro aluminum because the non-pro aluminum macbooks dont have firewire anymore (stupid move on apples part)
And a solid state HD is a hard drive that has no moving parts. Think of it like a really really big flash memory card, as appose to a 2.5 hard drive that has a spinning hard disk ;-). Theyre a lot more expensive and dont have as much capacity as a regular hard drive I dont really see it as worth it but thats your call.
Thanks, man. Appreciate the info. Im likely to be travelling it up a bit here, so, its possible the all aluminum chassis could be a difference worth the extra few bucks.
DEFINITELY going Pro on these as well.