Trying to get digital data from piezo sensor

I am currently working on analyzing data from piezo film sensors.. The problem is, sampling rate i am gathering from the sensor was too low then I planned. Sampling rate I want is about 1msps, since the frequency of signal I want is upto 300khz. But i found out it is almost impossible to get 1msps from arduino even though i use due... So, now I am looking for digitizers. I wanted single or 2 channel digitizer with maximum sampling rate about 1~2msps with small size. But i cannot find one. I am very very new about using sensor and gathering datas... Can anyone give this poor man a little help?

Take your pick.
The first results in the list are SOT-23-6 package. Doesn't get much smaller than that.

Your not trying to print anything between the samples are you?

A print statement slows things down enormously.