Recommendations for Server NIC

I currently have a black box home built server that I inherited when I joined current company. I dont know the make of the case, but it is using a Gigabyte Technology Co. / P55A-UD3P motherboard, Intel Core i7 860 2.80GHz & 8GB of RAM. It is running 2008 R2 SP1 and is primarily running HyperV to host Microsoft DPM in one VM and Spiceworks in another VM.

I have recently been having issues with the network card & networking configuration for HyperV [sharing the NIC for HyperV & OS] so I am looking to add a second NIC, allowing me to assign one specifically for HyperV.

Any suggestions / recommendations would be greatly appreciated. It will be connecting to 1GB HP ProCurve switch, as do the rest of the servers. It really only needs to be a single or dual NIC at most. It needs to be decent, but not expensive. sub $100 if at all possible.