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The datalogger talks SPI or serial... so it is not STAMP specific. Can you make it work with arduino? No reason why not... Arduino does serial and SPI. Your choice.
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You need to talk MODBUS. Can you make it with Arduino? Well, clearly you found the work done by Juan Pablo Zometa.
I guess there are your answers. It can be done.
The "doing" however, still seems to be very specifically up to you. You know what you need and you know exactly what you want to end up with. The gap between "having nothing" and "being done" is "the tinkering".