Off the shelf - would like to try before buy

Need some advice on where I can try the following headphones out. I live in Johannesburg.

Grado SR60i
Creative Aurvana Live!
Sennheiser PX100

Two of my sources are very portable - an iRiver L-Plyer and an Acer One Aspire Netbook - so it's easy for me to just show up for a "soundcheck".

thanx in advance


Russ