Hard Disk Transfer to SSD - 2007 MacBook and Lion
My favorite method is to install a Recovery HD onto an external USB drive and then do a final backup to Time Machine. You can use any USB flash drive that has 1G of space and can be erased or partitioned for your Recovery HD storage.

Now you can place the new drive in your mac and install a fresh copy of Lion and play around a bit to make sure it works. Once you are happy, erase Lion and re-install a fresh copy but instead of making a new account, just migrate over from the Time Machine backup.

For advanced users, using Disk Utility or SuperDuper/CarbonCopyCloner can be fun, but even knowing how to do all that, I prefer the opportunity to test my backup since being able to restore a backup is so overlooked and catastrophic when it fails on you should you need it.

I'd say save your money on the transfer kit unless you want that anyhow. No need to move things over and in fact, it's sometimes better to let the system lay out the files in order rather than block copying the old structure on to a pristine new drive. With an SSD, access times are so fast, you may not notice, but I'd rather have one process that works either way - SSD to HD or back, larger drive to smaller, etc...