I am curious as to what your network requirements are?
-Qty of sites to be interconnected
-Are all the sites within a metro area?
-Protocols/interfaces to be transported
-Bandwidth requirements between sites
What has caused your decision to move away from your current service provider? You might also consider a managed optical network.
There will definitely be a learning curve to move into DWDM, but this shouldn't be insurmountable given your aptitude to learn switching and routing.
Tom