OT: PCI Ethernet or USB 2.0 ethernet?

Friends, I have an instrument that has an intel motherboard with 400 MHz FSB PCI (not PCI-e). It has a 100 mbps Ethernet card and it would be very useful to get faster networking. The chassis of this instrument is such that I cannot fit a traditional PCI 1GB Ethernet card (I've tried). So I will have to go wifi (which I can make fit because I can remotely locate the wifi antenna). I have 802.11ac both 2.4 and 5 GHz available. While it certainly won't get as good a throughput as a dedicate GB Ethernet card, this is my only option. The question is, whether you think I would be better off using PCI wifi card or a USB-wifi adapter. I should mention the USB on this instrument is USB 2.0, the spec for which claims up to 480 Mbps. Anyone have an opinion which might get me better results? The wifi infrastructure is one constant in this scenario, just looking to see pci- or usb-based wifi card. Since this is wildly off topic, please respond to me directly so as not to bother everyone else :) W2hx at w2hx.com<mailto:W2hx at w2hx.com> Thanks Eugene