I have another possiblity for you.
Ikem-y pw Amun = Amun is my shield
You could also use only "Ikem-y Amun", with the same meaning. Sounds nicer, too...
I'm just a fan of the "pw" sentence, which is used in Middle Egyptian to state very clearly that "X is Y".
To see it in hieroglyphs, enter this code: M17 I6 G17 F27 A1 Q3 G43 M17 Y5 N35 A40
"ikem" is a shield in the literal sense, a shield made of wood and leather used in the Egyptian army. The metaphor of Amun as a shield can be attested in ancient Egypt: There's a personal letter in a papyrus (pGeneva D 407), Bu-teh-Amun writes a to Djehuty-Mesu:
“May Amun bring you home safely and that I can put my arms around you, that I can fill my eyes with the sight of you. And then you may fill your eyes with the sight of Amun, Lord of the thrones of the two lands, your protector and great shield, one against whom you may rest your back."
There are a few ways to say "protect", like "besa" or "khui" for example. As a sentence in Middle Egyptian, I think it would be transliterated to be something like:
"khwi Amun wi" or "besa Amun wi"
I believe it would have to be "Khwi wi Amun" or "besa wi Amun" - A dependent pronoun precedes the noun in a verbal sentence.
Just my 2 Euro-Cents... hope this helps!