Well, for my 500th post (yay me)

, lemme help you out here. Based on a rough guesstimate of Gallagher's locale from Zoneminder, Rational's distance calculater spits out a
range of around 2km - WELL within range (officially it can go out to 6km if the topo allows for it, but I've got one site out at 6.33km); so ..yea, the range variable is fine. But that's no help if the ground works against you, but the Midrand tower's on a hill on the other side of the freeway 'n Gallagher's up high, too.
So that's a 'go' for those two elements. About all you've got left to worry about is the actual building itself: if you try to get a signal from the eastern (Grand Central side) of the building, I'd say 'GFL boet' .. you've got a *mass* of building absorbing the signal! Bottom line? You wanna be on the western (highway side) of the building, pref in a window, and you should be good to go.
And, if not, there's always the BigAss(tm) antenna option!

(I jest, at that range, at most a pretty small one'd be necessary to overcome the signal suckage of the building).
HTH
-bdt