+1, imho, if you can go for a HR (with the bonnet bulge and 2 air intakes) then do so, otherwise I personally wouldn't be too tempted by the extra tax of the later pre HR cars.
The extra tax is nothing in comparison to the running costs and worth it just for the facelift exterior and upgrade interior and dash even if the op cant afford to go for the HR.
In standard form there isnt much between all 3 except visually and gearbox's in the revup and HR cars are much more reliable.
less tuning options for the HR. The revup will produce more power than the pre Revup once work is complete down to a variety of things including exhaust cam timing control etc.
Depends what your budget is and what you want the car for imo. These factors are the main deciding factors imo.