Hi Ema,
Robos are great. They are very small and fast and ever so cute. We've had ours since February and they are about a year old. I love to sit and watch ours eating and running in their wheels. Ours are quite tame so we take them out quite a lot and they run up and down our arms and legs.
They have really big personalities for such small animals. For example, Sprite, our little bully, will bite your fingers gently if she feels she has been out of the cage for long enough.
They are also extremely nosey for such naturally shy animals. If we go up to their cage and open the top we will usually see two little noses poking out of the nest. If we russle about in their food box they will come running out to investigate - greedy little things!
Best advice is to brave it and go for a pair, get them the biggest suitable cage you can find (ie that they can't escape from) and double up on wheels and sleeping areas to reduce the risk of territorial fighting. Just make sure that you get 2 males or 2 females as robos are the hardest hamster to sex due to their size.
Have fun with your new hamster(s)