If I were you I'd FIM, I'm trying it for the first time myself. When you FIM you only cut off a growth tip so you don't remove any growth.
To get the most you have to make the cut exactly right (might take some practice) and you must feed her nutes. Not too many, just what she asks for if you know what I mean. You also have to pay attention to the minor nutes as well as the major ones, if she's absorbing all nutes, major & minor, you might get a monster like this. (last message pic)
Personally I think the grower of that monster has another secret. Maybe some kind of root stimulator or something. I'll be experimenting as I go to find the secret.
Here's a chart to show you the cut, you take about 80% of the growth tip. Your supposed to cut the highest growth tip at the top on your stem. She'll stop growing for a couple of days after the cut, don't worry this is normal.
Also, it's a good idea to do it when you see the 4th or 5th node because it's also a good idea to cut off all growth below the FIM so all those Colas can get more of her energy. The longer you wait, the more growth you waste at the bottom of the stem.
Don't cut too early though, I FIMed a plant at 1 1/2" and she just stopped growing and hasn't restarted yet. Wait till you see at least 4 true nodes, 5 to be safe. This way you know she has a good enough root system to handle it.
Also, here's a chart of all the nutes and the absorbtion rate at different pH levels. The Sulphur and the Molybdenum is hard to find in nutes, and you don't want to handle raw Sulfur, that stuff is nasty and can be dangerous. I recently found some nutes will all major & minor nutes, it's the only one I've found after a month of searching. It's called Dyna-Gro, I think their site is dynagro.com but if not just do a search for dyna-gro or dynagro. Most of their fertilizers have all the nutes but a couple don't. You'll want to look at the nute list which is listed on the website to pick the ones that are right for you.
I hope this helps.
Good luck with your monster