AAA UI 1.2 and patch 4.09 m official don't play well together...
UP 1.8 works with 4.09 m, I do believe.
SAS mod activator works with 4.09 m.
Haven't used HSFX mods yet, but I do believe it will work with the official 4.09 m patch.
I currently run UI 1.2, MAT Manager, EnjoyRpatch 5 (I think that's the version number), StumStab 6.3. All these programs work well together. I installed all the programs after I loaded UI 1.2 from AAA, as they have features not included in the mod pack. This was my personal preference of course. MAT Manager has a few minor troubles with all mods for some reason, but read my post in this thread. It should solve any issues you encounter getting it to work....
If you just want a compilation of mods, go with the UI 1.2. It has just about everything you could ever want or need. Read the install procedure carefully, as some people get tripped up and they have problems getting it to run correctly. You should install UI 1.1 first, over IL2 v 4.08. Then add UI 1.2...it won't work correctly if you install it over 4.09. Always
read the release information before you install, even if the thread is 30 pages long. You'll find solutions to any troubles you may encounter 90% of the time.
If you want to customize the mods you install, go with SAS mod activator. Their work is geared more towards offline play and you can pick and choose what you want to add...however if you're new to mods, it may be a bit confusing to add their work. Read everything you can and ask questions over there...they have great support. www.sas1946.com/main/
...just have to register first.
Ultimately, any of these are great choices. It really just depends on what you want your IL2 experience to be.