Hi guys. I will have to do a fresh install on my pc when I get it back from repairs. What way would you suggest I install sonar platinum with regards file paths etc

Make sure you put the temp files on another drive (if possible).
Makes Sonar run a LOT smoother. 
For the most part, I only keep the essentials on the C drive.
Everything else (CW Content, etc) all reside on another drive.

I use the defaults. for a few reasons. I have the room, on my an SSD and the content is loaded instantaneous.
Really don't feel the need to set different paths for different things.
I like everything on my C drive. just like the default.
TBH, I don't put temp files on another drive (nothing against that).
I just delete them when they get more than 15GB in Sonar install files.
I keep a few roll backs. that's it.
 
this might help as well
https://www.cakewalk.com/Support/Knowledge-Base/2007013372/Clean-Install-All-Cakewalk-Software

I'm using the default cakewalk locations for everything. I just upgraded to an SSD (from a HD) for my boot drive - I'm keeping the OS, Sonar, content directories, VST's, and all on it. These are files that are never modified.
The only thing jinky I'm doing is keeping the Cakewalk projects directory on the old drive, which is now D, instead of C. This will keep the wear on the boot drive to a minimum. Just to make it super-kosher, I made a junction directory on C (the SSD), that points to the Cakewalk Project directory on D:, so it looks exactly like a standard install.

I do exactly the same as as SuperG, everything is defaulted to the C: SSD drive except Cakewalk Projects which is on my E: drive with a junction pointing from default location on C: drive. My downloads also point to E: drive as well and I just back them up to NAS drive and then delete them.

Hi. I use a custom setup. SONAR and plugins / synths installed to C drive, Content to D, and projects to E and F. CCC downloads to external HD. It has been very smooth on my end.
All the best.

It all depends on whether your C drive is an HDD or and SSD, and how many additional drives you have.  Give us the specs and you will get exact instructions.

Thedoccal
It all depends on whether your C drive is an HDD or and SSD, and how many additional drives you have.  Give us the specs and you will get exact instructions.

^^^ Exactly this.
 
Tell us about your HDD setup