The consensus now is for the Revision G, and is cheaper than the D! In R Tech (tuner in Hinckley) it held boost better than the D! IMHO get a remap with them, and according to them to replace the DV is a simple job. Beware thou, its a slippery slope! ;-)
Certainly by all means if somebody here can fit it for u, forget all above (at your peril)! Check on Search for part number for the G, costs about £37 from a dealer!