espguitarguy232 :
My question is should I go with regular PCI or PCIe x1 for better speed? I heard somewhere that with PCI you can only go as high as 133 Mbps due to the data transfer rates.
I don't think that's right. A 1000 Mbps connection is 1000 megaBITS. A regular PCI slot operates at 133 MBps -- that's megaBYTES -- which is more like 1600 Mbps. The capitalization of the B makes a difference by a factor of 12.5. PCIe x1 goes at more like 2.5 Gbps, which is more than you'll need for any Internet connection as well. So bottom line, either PCI or PCIe x1 is going to be faster than an Ethernet card, and you can use either standard.
I have actually heard of 2000 Mbps cards, but that's probably useless to most people because I don't think any ISP is going to give you service anywhere near that. Last year, they were excited that Comcast upgraded to 16Mbps in my area, although with the new DOCSIS 3.0 modems they may soon be breaking the 100Mbps barrier. So you probably are better off with a 10/100/1000 one than a 10/100 just due to future expansion.
I'd really just choose and 10/100/1000 card based on price and how many slots I have available.