I think most people will tell you to always buy in for the max (100BB) to maximize your potential pots. However, buying in for the minimum can have its advantages if you're playing a smart short-stack strategy. The SS game differs from standard ring play, so I wouldn't try it before reading a few articles.
Recently, I regularly bought in for 60BB at the pot limit tables. This was mostly due to bankroll considerations, and the fact that I was playing 4-5 tables at a time. However, as soon as my BR was healthy enough, I began buying in for the max.
If I were you, I'd buy-in for the max at one table. As soon as you start posting a profit at those stakes, you should be able to successfully add 2 or 3 tables without affecting your play too much. Just make sure you're winning first, or you could just end up tripling your losses.