Wedding Etiquette Please Advice๐Ÿ‘ฐ๐Ÿผ๐Ÿ‘ฑ๐Ÿฝ๐Ÿ’

Cece๐Ÿฆ
My SO is in the military and we are getting married!!!!๐Ÿ’ We are so excited but we hit a wall and need advice on how to go about this to our guests.ย 
Shortly after our wedding we will be moveing overseas. We talked to the base and they told us if we wanted anything at all shipped, we would have to send it a month in advance than we actually get there. If not then we will have to pay out of pocket to send over our gifts and it would take a month after we arrived for us to receive the gifts. My question is, would it be rude to ask our guests for money or gift cards instead of gifts? And how would I say it to them?