Memory upgrade type for ASG 220 Rev 2

Here is a question for those who know this model.

I have a test unit with 512MB of RAM and wanted to upgrade the memory. I looked up the memory model and it is:

Unigen 400 MHz 184 Pin 512MB
UG764D6688LS-GJFNCH

I could not find much of information based on the above information.

Here are my questions:

what I cannot determine is it ECC un-buffered or simply un-buffered?
The memory stick is low profile and I was wondering a higher profile would work?
Would the board take two 1GB sticks to 2GB of RAM?

Thanks in advance.