United Kingdom Colo Hardware

Recently I have gone from Dedicated Server to Colocation,

I contacted a UK colo and provided to them what I was currently hosted on and they advised me what I needed.

Web Server
Quad Core, 8GB Ram, 250gb HDD Raid 1

SQL Server
Quad Core, 4GB Ram, 250gb HDD Raid 10

Everything has been running fine.. Until now.

My websites have got alot more busy and Apache keeps using up both RAM & CPU although Apache was optimised this did not make much difference.

My main website is a vBulletin forum with about 100,000 users and anything from 1000 - 5000 users online.

I was also under DDoS Attack a few days ago which seems to have subcided.

BUT, now Im looking to expand my setup and have a few questions on how I should do it.

Here is how I think I should do it?

I have already purchased another Web Server, same spec as above and expanded my space in the Datacenter to 11U (1/4 Rack)

But looking to purchase:

Load Balancer
I have been looking at the following Load Balancers... any suggestions or any info on if these will do what I need?

[url]
or
[url]

any idea what the difference is between the above?

NAS Storage

as above

[url]

or a Dell Storage server?

So, It would be multiple Web Servers reading from the Storage Server.

I would also like to purchase the following so I have more control over the servers

KVM

This one?
[url]

or this one?
[url]

Remote Reboot
Switch
Firewall