I'm brand-new to RPi and Debian Wheezy, but used the 4-step install
If you take a look at the version of installed Lazarus, you will find out why many people are trying the other way. I have managed to install latest Lazarus with a trick, because the common SVN way reports many compilation errors.
First, you need to increase Raspbian default paging file to 512MB.
Next, you install FPC from Raspbian repository as you have mentioned.
Finally, you install Lazarus from SVN.
Last step worked with Lazarus 1.02 at the time when I did it initially, but it might be a problem with 1.08 or current SVN since they need FPC newer then in Raspbian depository. So, try this method with Lazarus 1.06 or older since they still compile with FPC 2.6.0.
EDIT: comment from chrnobel reminded me to report that I had to lower GPU usage (I think 16MB was minimum), and I compiled without X running. These settings and swap file increase were essential for successful compilation of many things flagged as 'non compilable' by some users in various forums.