I'm glad that you're using inductive current measurement!
IMHO, the datasheet you linked to looks similar to the cruddy datasheets that I see for ~90% of the arduino shields.
EDIT: Seems like the Pulse Electronics sidewinder series need a special sensor or SOC that supports it.
So, they won't work without additional support circuitry. Off hand, I don't know of another current sensor with good accuracy and linearity over the range that you need.
I've used the ones by Pulse Electronics before. They work, they have real specs, and they have real data sheets.
Even at the low end of their measurement range (0.1amps) they have an error of less than 1%. By ~10% of full scale, the error goes down to ~0.05%.
The PA3206 or PA3208 would be a good choice. You don't want a "huge opening" for the sensor and a small wire.
PA3206NL 460?V/A460 0.1A–>40 A
PA3208NL 460?V/A460 0.1A–>120 A
Some links:
http://www.pulseelec....com/sidewinder
http://www.pulseelec...nload/3775/g043
http://productfinder...sheets/P698.pdf
http://www.st.com/st.../CD00289924.pdf
PA3206
PA3208
Good Luck!