You mean like a Redstone rocket?
This was too obvious. Isn’t the Titan IV a super rocket? Can’t extra stages be added if they want to go to the moon?
I wish I knew enough about the technical aspects of this issue to know who’s right. The modified military rocket approach seems to make sense - it’s readily available and would build on proven designs. But I just don’t know enough about the safety factors and other considerations to really say for sure.