Question: We have just received a device with 10Gig BaseT ports (for copper cable with RJ45 endings) that needs to be connected to a Cisco Nexus 5548. This switch only has SFP+ ports and we're connecting them right now using a couple 1Gbps SFP. We really would like to use the 10Gig connection.

I googled 10Gig Media converters and found some brands but i have doubts regarding stability and compatibility. The final scenerio would be like this:

[Nexus 5k]--[10G SFP+]---Optical Fiber Jumper---[Media converter]--Cat 6a--[DataDomain]

Does anyone out there have a similar combination of equipment? How has it worked for you?

Answer: 
So the obvious question is how much all that media converter stuff costs versus just buying a cheap 10G NIC with an SFP+ port and using fiber, twinax or AOC to achieve a sane and supportable result? Will the converter work? Sure - most likely... will it be supportable and stable? It's definitely outside the realm of best practice.
The third party components will work fine. If you find otherwise, I would love to hear back...

Don't resell them as Cisco though. People have gone to prison for doing so...

Also, if you tell Cisco TAC they will void your SMARTnet contract out.