Anita,
I believe that for your application, a 12-bit DAQ will probably suffice. If you have a computer already with an open slot, this would work just fine.
Therefore, I think you'll need:
AT-MIO-16E-10 Data acquisition board
(100 kS/s, 8DI/16 SE analog inputs, 2 DACs, 2 counters, 8 digital lines)
SH6868EP cable
SCB-68 Shielded I/O connector block
And, of course, a copy of LabVIEW.
If you are truly reading a current, not a voltage, you will need some external CVR (current viewing resistor) to read a voltage. This is just a very low resistance put in series with the transformer, and a voltage reading across the resistor is taken. Current can then be calculated.
That should do it!
Mark