HP storage arrays - multiple channels?

HP storage arrays - multiple channels?

Our SQL server is becoming pretty heavily loaded, and all indications
point to the disk channel being the bottleneck. The current HP server has
a fairly low-end array card, and we're looking to augment this server with
a Smart Array card and external storage array with SSD drives.
Current config is:
DL360 G7
Smart Array P410i
Windows Server 2008R2
32Gb RAM
Current array is 2 x 300Gb SAS RAID1 logical drive for boot/OS and 1 x
120Gb SATA SSD drive for data.
The database server hosts one fairly large database (~100Gb), containing
both live and historical data. For many reasons, splitting the database
isn't an option, so the current thinking is to have multiple logical
drives on the new array, each on it's own channel, and then split the
database into logical SQL partitions.
For example, the array might have:
2 x SSD (RAID1)
2 x SSD (RAID1)
4 x SSD (RAID1+0)
Currently, we're looking at something like a D2600 with a high-end Smart
Array card.
In order to get the maximum performance, we really need each logical drive
to run as fast as possible. HP's specs suggest that their top-end SSDs
could come close to max'ing out the 6Gb connection that the Smart Array
cards support.
However, some of the bigger SA cards suggest they support "multiple
channels"; what's not clear to me is how this work. Does this mean, with a
single cable from SA to D2600, each RAID set could be configured to get
it's own 6Gb channel? Or is 6Gb the limit on the interconnection, and if
so is there any configuration option (or even different HP product - not
trying to get around the "no subjective questions" rule, honest :) ) that
would overcome this limit?
EDIT: I can't see any HP server that will do it, but if there is a decent
Proliant box that will allow me to split the internal drive cage into two
(or more) channels, that might be a "Plan B" - does anyone know of such a
server?