Is getting a date tattoo a bad idea?

My dad died 6/21/06. I was 24 yrs old and my brother was 21. It was a sudden heart attack and it's been really hard on us. We want to get a matching tattoo but can't decide what would be appropriate for both of us. I was thinking about the date but in roman numerals (VI XXI MMVI) we want something special to us but not a in memory of and cross kind of tattoo. Is this a bad decision? I just don't know if a date represents my dad the way we want. Any other ideas?