Aside from the obvious answer, why is a reservist going overseas to a war zone to begin with, a more appropriate answer would be what is your role? I mean no offence by my first comment (jeez, what is the army coming to when you have to worry about offending people).
Like I said, it is determined by your role. Are you a rifleman, a C9 gunner, a C6 gunner? Of course it is by personal preference, but that is more of a comfort value. The obvious choice is modular. Make it so you can attach and detach pouches as you see fit. If you go with a vest then you naturally have less room since you have to leave the back open for your ruck sack or patrol pack. If on day patrols then a detachable rear back pouch is one option but keep in mind of water IE. camel back. Just go with a separate patrol pack although less comfortable.
The other option is a webbing style. Although it is unpopular it may be what your looking for. Modular or fixed it can alleviate some problems and it will carry more and interfere less with a back pack. Some like it. Some don't. You can consider it.
Whatever your choice, flexibility is the key. You are no doubt aware the TV is grossly inadequate. The bigger question is wether or not you are allowed to wear it.