Hey smokerz, howd it hangin dude? I would have to say that MOST of the growers on this forum would not recommend topping an autoflower as their limited lives mean they might not fully recover and damage your yields. LST is certainly the safer option and you can get some pretty spectacular results. There are quite a few threads on the subject and some journals that are worth reading, ill try and find you some links.
It's a good idea if you head over to the introduction section so everyone gets a chance to say hello, and then when you're ready, start yoursrlf a grow journal. This is the best way to get the most out of afn, and makes it easier for prople to help you out.
Peace and happy growing!