What I'm looking for is a solution to connect workstations with RJ-45 Ethernet NICs with a workstation with SFP/SFP+ NIC.
I found that many switches have both RJ-45 and SFP/SFP+ ports available, however, normally the SFP/SFP+ ports are uplinks used for switch-to-switch connection. From the definition of "uplink" (from http://www.linfo.org/uplink_port.html and Why do some switches have uplink ports?), it seems that the only difference between a uplink port and normal "downlink" port is whether the TX/RX is crossed-over or not. So for RJ-45 based uplinks, if proper twist-cables are provided, I take that a uplink can be used to connect to a workstation (rather than another switch) just like other "downlink" ports.
Now here is my question, when the uplinks are SFP/SFP+ ports, do I need to use special "twisted" (probably not physically...) fiber cable to connect to a workstation with SFP/SFP+ NIC? Or, if direct attach cable (copper one) is used, do I need to cross-over the transmit and receive pair(s)?