if 30£ isn't too much I'd go for an i3 instead of the Pentium, but that's just me.
Couldn't the OP just go i3 Haswell which supports up to 3 monitors and something like a B85 motherboard without even a need for a graphics card?
asus H81M-Plus has dvi/vga/hdmi so should be able to manage 3 monitors, ive only ever used hdmi on mine..
for office you dont technically need a graphics card, a lot of your every day ones dont, i just put it in there to make up the cost and just incase the intel graphics wouldnt be up for the jobs in hand.