Borg (and others), I think that it's great that you can get the whole family involved!
I know aikiko, karate, jiu-kitsu, and a few other Japanese words...
One of the most effective styles is Mexican Judo...
Personally, I'm not really concerned about rank.
I took a couple of years of Tang Soo Do back in the day and, even then, I missed a few testing opportunities (never got my black) but it was no big deal.
These days, all the guys in the different training circles I frequent are also really not too concerned about rank. Some of them have earned traditional ranks but it doesn't make that much difference. We pretty much know who is good and who is better (regardless of what belts each of us may possess) and there are no attitudes (well, not among the guys that regularly train together).
If, however, I was limited in learning/training by a ranking system, then that Would also be a concern to me...