I just purchased the 2 amp power cab system. If i have correctly understood what info i have managed to find at this point, the command station is the upgrade for this? Also, does the command station make this into the next higher system that has all of the bells and whistles? I'm just getting started in model rr and have alot to learn. Also bought a Athearn Genesis GP 15 with the Tsunami decoder. Haven't recieved either item yet.
Oh, an NCE power cab and Athearn Genisis GP 15 with tsunami! That's starting out in style.
There is a defined upgrade path and an alternative I could suggest, but first you need to decribe some operating parameters to determine what you really need.
How many locos will you run simutaniously?
How many people will operate the layout at any one time?
The basic NCE system is quite advanced for a basic system. You can add a second cab to that system. The cab can be either another power cab or one of the engineer throttles. The main limitation with this system is the power avaliable. Sound locos draw more miliAmps (mA) than non-sound locos. I think a rule of thumb of 1 amp per sound loco will ensure you have plenty of power avalible. Thus the basic power cab is fine if you run two locos (seperately or consisted). This will do for a small layout.
The offical step up is to go for the pro cab system. The power cab fits right in with it as an extra cab. Pro cab is an excellent system which is hard to fault on technical grounds. My club uses this one. However it is not cheap and a massive overkill for smaller layouts.
Other ways to spend money are to go wireless. There is a wireless pro cab system, even more expensive than the pro cab. My father lashed out an bought it recently so I'll get to see how it runs soon. Once again, really best suited for large and busy layouts.
These pro cabs have 5 amps avaliable I think. Then you can add boosters in seperate power blocks. As you can see, fine for lots of locos, especially sound loco consists.
So, my intermediate suggestion would be to have a look at the smart booster SB-3A. This is take up to four cabs (including engineer throttles). It has 5 amps avaliable. Once again the power cab fits in nicely as an extra cab and programmer for the work bench. This will happly run five sound locos at once. For most people's home layout, this would seem to be enough.
Here's some links:
http://www.ncedcc.com/
Other ideas:
http://www.dccconcepts.com/
And my personal favourite system (for the work bench mainly)
http://www.sprog-dcc.co.uk/