Mmm, I see little harm in moving the wiring from the 110VAC from the transformer to the 230VAC mains. As long as you do it behind a Fuse (REMEMBER ULLY, did you install yours yet on the WOW ?

).
I mean, moving some wires from one connection to another is not actually like harming a cab.
The 230V one's Ully found are cheap _and_ incl. free shipping. I doubt any US option would be cheaper esp. because of shipping.
But if you are extremely anal, or not capable of moving the wires to the 230VAC connection, try to get 110VAC ballasts.
By the way Ully, if you want to go very environmental friendly, get an electronic "ballast". These feed the tube with very high-frequency voltages. This increases the stability of the light (no flicker, if you are already capable of seeing it). It also increases tube life and decreases energy consumption.
The downside ? They cost about 10 times more......

Seriously, those type of ballasts are only cost-efficient where TL light is on for long time (for instance offices, let's say 10 hrs.per day, 5 days per week, at least). On our cabs, it will hardly make a difference.
Other alternatives: cold-cathode tubes (expensive) or LEDs. I'd still go for TL anytime.