It depends if you want High Def or not... personally I'm a big High Def fan.. and given that the HDV camcorders also can shoot excellent SD, I'd go that way (so not the Sony PD 170, or Panasonic AG-DVX100A).
Technically speaking the Sony HDR - FX1 is not a "professional" camcorder, as it is sold by the consumer division rather than the business division. The Z1 is the professional version of the FX1.. but it is well over £3000.
There is also the new FX7, which is about the same price as the FX1... smaller, lighter, has 3 CMOS vs. 3 CCD for the FX1. The only person I know who has used both thought the FX7 was slightly better overall...
http://www.camcorderinfo.com/content...CMOS-Chips.htm
FX7 available here for £2200
http://www.purelygadgets.co.uk/showp...hp?prodid=2898
The pro version of the FX7 is the V1... it is slightly cheaper than the Z1, about £3000 with VAT.
So for £2000, either the FX1 or FX7....