bitflipper
What about Cyclone? That's still in SONAR, isn't it?

 I have never used it but that seemed like it was ahead of it's time.
 
 Free sample players are UVI's player and DiscoDSP Highlife free version.

I sampled my real drum kit , railroad spikes, blocks of wood you name it. 
Record them as standard 44.1/ 24 bit waves. 
You then load them into a wave editor and cut the front and tail ends as close as possible. 
It's also a good idea to maximize the level. 
 
Session drummer has a folder with all the kits in it.  
C:\Program Files\Cakewalk\Vstplugins\Session Drummer 3\Contents
 
I made a new folder for "my samples" 
You need to load a kit into SD before it will play, it will be ghosted out until you do. 
Right click on PROG  at the bottom and load a kit. 
When I find a kit I like I save it as a pre set so it's easier to load. Kits are saved with projects. 
You can load individual sound to each drum part. 
You click on the drum , example snare, now use the DRUM menu at the bottom and load the sounds you made. 
You can also right click on a drum and it will open a Load Instrument menu. You might have to browse to the above location. 
Real spooky to hear my real drum kit playing. 

mettelus
+1 to Session Drummer 3. Here is a quick 3 minute video that walks you pulling sample slices with AudioSnap 2.0 as well (I forget which SONAR version you have).
 

You can do that from the browser too.
 
Just drag & drop samples into the slots (images).
 
Exactly what OP is asking, I think.
 
Pretty handy actually.

+1, Session Drummer gets overlooked a lot for its simplicity, but it doesn't care "where" the sample comes from and will play whatever you give it (drag/drop from wherever your samples are).