I am setting up SAN Copy and I need some advice on the best solution here.

I have a new VNX 5300 w/(2) 8GB I/O modules and the SAN fabric of (2) new Cisco 9148 switches.

My existing environment consists of my SAN Fabric of (2) MDS 9509's ,and two arrays, a CX-380 and a NS-960.

For SAN Copy sessions from the existing arrays, should I cable the existing fabric into the new fabric? or should I cable the existing arrays directly into the new fabric? (ex, cable CX-380 SPA-0 & SPB-2 & NS-960 SPA-5 & SPB-4) directly into new Fabric or cable to two fabric together?

The existing arrays (CX-380 & NS-960) and fabric (MDS9509's) will be retired within 3-4 weeks and hosts and data are being migrated to the new fabric and arrays so I don't know if I want to go the ISL route with the Fabrics or not?

Any advice, hints or tips are appreciated.  Links to documentation is appreciated as well.