DEL T7600 with 10GB compatibility!

Firstly. Hi too all from Chile!! :D Hope everyone is doing well..

My question is regarding adding a 10GB NIC (over rj45) with our Dell T7600s and Dell 7810s

1. We purchase (without checking) quite a few x550 t1 (one port RJ45) and quite a few x550 t2s (dual port RJ45).

2. Both cards work fine with the new Dell 7810s 

3. We are having difficulty booting with the dual cards on the Dell 7900.. strangely enough the single port x550s work fine. but the dual cards stop the booting process with a blinking cursor.

It is very important that we get a 10GB dual port card working on this computers (the T7600). We are even willing to buy new x540 t2 cards if there is a way of knowing if they would work on the above-mentioned computers. I read from an earlier post that there is a special BIOS to get this kind of networking enabled. 

Please advise. we are desperate

Best regards