CBA (Community Based Addons) is used for a whole host of Mods, you'll find that a lot of stuff needs it so is worthwhile getting anyway.
Adding mods and setting things up is simple, just create a new shortcut, in the case of I44 you would just create a new shortcut with the @I44 mod added in the Target line, you will also want @Carraigdubh on there as well as we will be using that on saturday.
To expand - in the target line of the shortcut you list the mods you want to load with the game there, here is my I44 shortcut target line in full, you would just change what is applicable to you: what mods you have and wish to use, your user name ofc and executable location. Here i'm playing with the beta patch so it looks a little long winded but from -nosplash onwards would be applicable to you:
"C:\Games\ArmA 2\Expansion\beta\arma2oa.exe" -beta=Expansion\beta;Expansion\beta\Expansion -nosplash -showscripterrors -name=jRides -mod=@CBA;@CBA_A2;@CBA_OA;@okt_NoBlur;@sthud;@stmov ement;@DC;@I44;@Carraigdubh
Its that simple.
The mods wont interfere as long as your only adding specific mods, for instance I have several shortcuts for starting Arma2 vanilla, Arma2 beta, DayZ and I44. While all the mods are sat in the same place the target line of each shortcut just loads whats needed. There are programs that do this too - where you can set up what mods you want to install but I could never figure it out so someone else will need to comment on that.
While your on the Armaholic site you might want to take a look at STHud and STmovement, both are excellent little mods (tweaks really) and worth your time. They will probably be recommended to you if they haven't already, and of course you don't already have them.