Hi Pete,
I bought my first modular system about 6 months ago; It's a 'custom'
(not basic) system only made of Doepfer modules. I chose the modules
by reading the doc on Doepfer website for each, maybe that's what you
should do too, they are quite explicit, even for newbies, and will
give you a good idea of what you need and what you don't.
Also, doing this will help you no being completely lost and confused
in front of your brand new system when you'll recieve it !

I don't know where you're from, but there's maybe someone or some shop
in your area who could demonstrate modular stuff for you and learn you
the basics.

Buying a new system is an important decision to me and should be
prepared carefully, good luck !

... and sorry for bad english !
Max.