I use the Sigma 150mm F2.8 EX.  I chose this because I wanted the longer focussing distance to capture bugs etc. The quality is very good both optically and build, it is available at good prices.   I didn't suggest this lens in your other thread because for your purpose there you do not need the extra range it gives and this comes at a price.  The price is that it is lot heavier than the 100mm and faster shutter speeds need to be used to get a sharp capture. You could end up with very shallow depths of field which would not be ideal, or increasing the ISO again not good for what you want the lens for.  There is no point in burdening yourself with these disadvantages when they are not outweighed by advantages in the type of shot you want to capture.

And every one said, 'If we only live,
We too will go to sea in a Sieve,---
To the hills of the Chankly Bore!'
Far and few, far and few, Are the lands where the Jumblies live;
Their heads are green, and their hands are blue, And they went to sea in a Sieve.

Edward Lear
http://www.nonsenselit.org/Lear/ns/jumblies.html