if you can find them (check
www.ebay.de) a pair of Gefell MV592's with UM70 or UM71's make brilliant overheads. there's something about the lower output of the older Gefell's that just seems to sound much smoother.
for a bright but smooth sound, a couple of 451's with BLUE's lollipop capsules should also fit the budget.
either of these options would work great on vox as well.
but if OH is your main concern, check out the AEA R88. holy ****.