Windows 7 - Upgrading laptop hard drive, wanting to copy all files onto new one

I have a Dell inspiron 1545 with a pretty measly hard drive of 135gb. I have an old hard drive from another laptop which is 320gb and i'm wanting to upgrade. I have done this before but i just used all the installation disks to reinstall windows and everything onto the new hard drive. This time however, i want to be able to copy the whole contents of my current hard drive onto the new one so that when i swap them over and i boot up the computer it contains the operating system, software and files that are currently on the 135gb hard drive. I presume there is some sort of wires, software and housing that i might need to achieve this. So far i have been pointed in the direction of this software pack (Apricorn EZ Upgrade Universal Hard Drive Upgrade Kit (SATA and PATA 2.5" Notebook Drives) Deals, #EZ-UP-UNIVERSAL - Expansys.com UK) but i was wondering if there was a cheaper way to perform the required task.

I was also wondering if the new hard drive will affect battery life. The new one spins at 7200rpm compared to the old at 5400rpm.

Thanks for any help anyone can give me.

Any USB carriage that can hold a 2.5" SATA drive would work. Then you can use something like Macrium Reflect to clone the internal drive to the external one. Once that process is complete, shut down the laptop and swap the drives.

If the new drive spins at 7200 rpm, than it will reduce the typical battery life of the laptop...but it will offer slightly better performance.