Broforce Airsoft has the best brands of bb's in it's assortment, including; Xtreme Precision, G&G, Nuprol, Madbull, Geoffs & Green devil. We only sell certified biodegradable bb's, so you can play on all Dutch and Belgian pitches without any problems.
.20g - .25g bb's are used indoor. Because you have virtually no negative influences from wind, for example, heavier bb's are superfluous. In addition, the short engagement distance often means that you do not have to shoot over very long distances.