To measure the wave form and voltage peak to peak for three phases accurately, I would recommend the ADC-212/3. To do this you will need two units since it is a two channel scope.
The data aquisition software is Picolog, this software is capable of using muliple convertors. There are two methods available for collecting the data one 'Real time continuous' where you can sample at time intervals of one millisecond or slower, in this method you are restricted to one million samples. The second is Block mode where the unit can sample as fast as possible, but is limited by the buffer size.
The units standard connection is to the Parallel port, but can be connected to a USB port by using the USB to parallel adaptor..
Unfortunately, we are unable to recommend our product to measure phase angles.