I'm no avocado expert, but since no one else is helping you... Maybe Holiday? It's a smaller tree. Not sure about season though. There are so many good varieties, it really depends on what you like and more importantly what your growing conditions are like. I think GEM was supposed to be pretty good as well and be a smaller tree, but you'll need to double check. The season for GEM is supposed to be different from Reed.
I just planted:
Reed
Pinkerton
Sir Prize
GEM
Holiday
Fantastic
The Fantastic was on clearance at the end of the year at Lowes and I could help myself. I don't know much about it yet, so couldn't recommend. The other ones seemed to have a lot of good reviews.