Laptop question

Hey, I need to buy a laptop asap, and I have a few quick questions. I noticed the laptop thread, but it’s just people posting what model they have, so it doesn’t exactly address my inquiry. I’ve found a few other threads that discuss some of the concerns I have, but sometimes the information is slightly contradictory, or just not specific to my situation.

As it is now, I have an actual home PC that was decent at one point, although it’s getting quite slow (it often slows down and becomes inefficient when I reach a certain number of tracks, mostly because of the effects/ect.). As I’m aiming at playing live soon (as well as produce on the road), I figured a laptop would be a good investment. Money isn’t an issue, as I definitely want something very quick (considering my current issues with speed/performance).

I’ve read about the whole AMD/Intel thing and from what I understand, while both are obviously quite good, Intel has a slight speed advantage. I’ve read AMD is a good “bang for your buck”, but I don’t mind spending more if an i7 is faster. I have no other use for a laptop than to produce music (so I don’t care about graphics/gaming/etc.), so speed/performance is my main concern. However, I’ve read some posts saying i7 doesn’t make a big difference from i5, because of Cubase doesn’t support “Hyper-threading”.

Put simply, here are my main questions:

-Hyper-Threading aside, is there still some significant speed advantage with an i7 (over i5, or even AMD A-10)?
-I read SSD drives are much quicker than HDD. Is this a big advantage for Cubase?
-The models I’ve looked at have 8G of RAM. Would upgrading to 12 or 16 be virtually pointless? (I’m sure the marginal benefit is less than upgrading from 4 to 8, but I would still consider it if it makes a difference.)

Are there any other main factors to consider that will affect speed/performance significantly? As I said, money isn’t the issue (within reasonable terms, of course), as I want to make sure everything runs smooth. I’ll keep recording my hardware synths from my home set-up, but since I’ll be using mostly softsynths and programs like Nerve on the laptop while I’m on the road, I want to make sure I have the proper requirements.

For the record, I use Cubase 4 Studio (it’s been working fine for me, so I just never took the time to upgrade — although I assume I probably will sometime in the not-too-distant future).

Anyhow, thanks in advance, I sincerely appreciate any help/advice. I almost bought a laptop today, it’s just the guy selling it to me had little knowledge of music production, so I figured I’d check this forum (as people here are obviously much better suited to answer my questions).