There is no single, universally accepted "Aramaic" language. Aramaic encompasses a family of dialects, some of which are mutually unintelligible. Therefore, a simple translation of "God Amen" requires specifying which Aramaic dialect is desired. Different dialects will yield different translations.
To provide a more accurate translation, I need to know which dialect you require (e.g., Biblical Araic, Syriac, Jewish Babylonian Aramaic, etc.). Without this information, I can only offer a few possibilities, each with caveats:
Possible Translations (with caveats):
Biblical Aramaic (a general approximation): אֱלָהָא אָמֵן (ʾĔlāhā ʾĀmên). This uses a common form for "God" and the standard Aramaic word for "Amen." However, the exact spelling and pronunciation could vary depending on the specific biblical text and its interpretation.
Syriac (a general approximation): ܐܠܗܐ ܐܡܝܢ (ʾAlāhā ʾĀmīn). This uses the Syriac script and slightly different spellings. Again, variations exist within Syriac dialects.
Other Aramaic dialects: The translation would differ significantly depending on the chosen dialect. For example, Jewish Babylonian Aramaic would have different vocabulary and grammatical structures.
To get a precise translation, please specify the target Aramaic dialect. Providing context (e.g., the sentence's purpose, the intended audience) would also improve accuracy.