[j-nsp] Best design can fit DC to DC

[R LAS]

Hi all
a customer of mine is thinking to renew DC infrastructure and interconnection among the main (DC1) and secondary (DC2), with the possibility in the future to add another (DC3).

Main goal are: sub-second convergence in case of a single fault of any component among DC1 and DC2 (not DC3), to have the possibility to extend L2 and L3 among DCs, to provide STP isolation among DCs, to provide ports on the server at eth 1/10Gbs speed.

DC1 and DC2 are 35 km away, DC3 around 1000 km away from DC1 and DC2.

Customer would like to design using Cisco or Juniper and at the end to decide.

Talking about Juniper my idea was to build and MPLS interconnection with MX240 or MX104 in VC among DC1 and DC2 (tomorrow will be easy to add DC3) and to use QFX in a virtual chassis fabric configuration.

Does anybody have these kind of config ?
Is it stable QFX ?
Any other suggestion/improvement ?

And if you would go with Cisco, what do you propose in this scenario ?

Rgds