The "recently purchased" model AirPort Extreme, if you purchased it within the last twelve months or so, is the "current model". If you have two of them, the answer is obviously yes. If you have two 802.11n Extremes, basically any of the ones built since about 2007, the answer is still yes.
I don't believe you would have asked in those words if you were in possession of two apparently identical Extremes though, so please indicate which two models you have.
Use this page: Identifying AirPort hardware
"Fast Ethernet" was typically used to describe 100Base-T to distinguish it from the relatively slow 10Base-T. Apple discontinued models with 100Base-T Ethernet ports over five years ago. They were the original "round" AirPort Extreme model.
If you have one of those, the answer becomes more complicated.
"Fast Ethernet" was superseded by 1000Base-T. It has become more commonly known as Gigabit Ethernet.