Switch with 10 GbE uplink communicating?

[valikoo]

Hi! I'd like to buy the "H3C S5120-28C-EI Gigabit Ethernet Switch"

But I'm not sure that it's for me. This is my desired configuration:

There ara 8 clients for video editing (Macs Pros) and 2 Severs

{Mac1}  {Mac2}  . . .  {Mac8}   

      ||            ||                 ||

      ||            ||                 ||

  (2 Gbits Agregated links)

      ||            ||                 ||

      ||            ||                 ||

               ||             ||

               ||             ||

  (20 GbE Agregated links)  

               ||             ||

               ||             ||

    {Xserve1}     {Xserve2}      

            |

            |

(Fibre Channel 16 Gb)

            |

            |

    ((( RAID )))

1) Can I use S5120 for this purpose?

2) Can I use "3400cl" ?

3) Your suggestions for minimizing cost?

4) Can I get 20 Gbits (agregated) or 10 Gbits only ??

Thank you!