The only issue with downlighters is positioning is dictated by joists and other obstacles like pipes etc! eg, on my landing I wanted two central to the stairwell, because a roof joist was smack back central I ended up with one to the left & one to the right, it actually looks better though! For your large room I'd have a 3 or 4 gang switch, one(two) to switch the pendant(s) and the other two to switch the downlights. If you have a long row of them make them alternate, eg, row of 8, one switch controls 4, so you would have:-
x on x off x on x off x on x off x on x off
x on x off x on x off x on x off x on x off