Hey Andrew,
the difference between 110 V to 220 V models is that with same power rating (measured in Watts), both VFD and spindle suck double the current at 110 V than they do at 220 V which means if you choose 110 V, you need wires with the double cross-section area and also double the current allowed for your circuit breaker.
You are interested in a 2.2 kW spindle, which is a reasonable size. The 2.2 kW (CT mode) output power, 200-240 V single-phase input Hitachi VFD Model No. WJ200-022SF (Manual) is practically identical to Omron MX2 VFD Model No. 3G3MX2-AB022-E (Manual). Note that the input power of these models is 3.8 to 4.5 kVA (depending on exact input voltage) which means 19 A current on input side. Circuit breaker is recommended to have 30 A and the wires for the single-phase input to have 5.3 mm² cross-section area (AWG10). If you want thinner wires and lesser current, you can use three-phase input instead of single-phase input, but while here in Europe it is common to have 400 V three-phase electricity in every house, as far as I know this is very rare in the U.S… I don’t know how it is in Canada?
Note that the same wire sizes and circuit breaker amperages are needed for the cheap chinese VFDs and spindles, it is a matter of current and not of provenance. The difference is that Omron and Hitachi VFD manuals tell you about it while cheap chinese manuals don’t.
Hitachi and Omron do not offer VFDs for girly power 
errm I meant for 110 V, but at 110 V, this would mean double the current and therefore double the wire’s cross-section area, so now you know why they don’t offer them.
Note that in the U.S., many people have split-phase electricity (two 120 V phases shifted by 180°) which means even if they seem to have only 120 V outlets (which is between one hot and neutral) they usually have 240 V in their homes (between two hots of different phases) so an electrician can easily install a circuit with a 240 V outlet and circuit breaker.
Yes, on 2.2 kW and higher power models.