Age and size doesn't make much of a difference, just personality. I've found that when an adopter approaches us about finding a friend for their rabbit, they often don't see the key things needed. I can't even tell you what the key things needed are because I tend to act on instinct. From the point of view of the rescue I find it easiest when I see the bunny and watch their behaviour and then ask the adopter questions relating to what I have seen.
I guess just get to know your bunny really well and then describe him. Date wise, we have had people bring their buns for two hour journeys to date and it's always been worth the journey to all the bunny to pick for themselves, however, not all bunnies travel well.