Why rehash what's already been written but here's the lowdown on all 3:
M-Audio Firewire 1814Presonus FirepodMOTU Ultralite (I think you meant Ultralite because the Traveler is more expensive at around $850.
It all boils down to I/O preference. If you need 8 XLR mic inputs, the Firepod fits the bill, plus s/pdif coaxial I/O, you get at total of 10 inputs and outputs.
The Ultralite has 2 XLR/TRS combo connectors vs. the Firepod's 8. S/pdif is also coaxial so you get a total of 10 inputs. On the Ultralite, however, the main outs and headphone outs are separately assignable so you get a total of 14 outputs. The Ultralite can also function as a standalone digital mixer when not connected to a computer.
The M-Audio FW 1814 has 2 mic pre amps, but it's 6 other analog inputs are unbalanced as compared to the other 2. The 1814, however, also has ADAT capability plus the coaxial s/pdif gives you a total of 18 inputs, but only 8 of those are analog. Analog outputs are 4 plus ADAT and s/pdif gives you a total of 14 outputs.
Also note that the Presonus and MOTU offer AKM converters similar to those used in Apogee and RME interfaces. I cannot determine what converters the M-Audio uses.