Bill's advice is good. Mini line arrays are great if you have a reasonable budget, but you really need two for all but quiet gigs, so the cost gets a bit steep. Quality 10+horn boxes on poles and a single decent sub on the floor will have minimal visual impact and can be very capable. Incidentally, Bose are not a true array, in that the drivers in the columns are angled to each side, rather than all pointing directly ahead, which gives good coverage at close to medium range, but lacks the 'throw' of an array.
RCF are always a safe bet, as Phil suggests, for good but not pricey PA speakers. They occupy a sweet spot between budget and costly. For £2k, you could get a pair of RCF ART310s plus a 905 sub, which would be a very tasty system and would, I reckon, out-perform your Behringers, especially when it comes to clarity.