Hi, I'm trying to find out exactly what they mean by a "streamlined version" of sonar?  Does that mean some features will be missing?  I have the last updated version of SP on my computer but i need to upgrade my hardware and i don't want to lose certain features of SP.

Take a look at the sticky thread above about the various versions of Cakewalk/sonar.

There are no features missing - the feature set is the same as Sonar Platinum.
 
It's streamlined, because there are no 3rd party bundled plugins as with Platinum (e.g. AD2, Melodyne etc), and none of the premium Cakewalk vsti's (e.g. Rapture Pro).
 
If you want to use all the extras you had with Sonar Platinum, make sure you install it on your new PC before installing CbB.
 
M.

As said above. 
For a new computer you need to install Splat first, then CbB 

You don’t “need” to install CBC first. If it’s already installed and you want to install SonarPlatinum next then just make sure that you use the same VST paths in both programs.

Of course as a general rule of thumb it’s is usually the better option to install older versions of a program before newer ones.

I just did this on a new PC build as I wanted to see exactly what was in CbB before I installed SPlat.