My advise is to go for a facelift despite the tax. Within a few months you'll want the facelift rear led lights which will cost the tax difference for near 2 years, then you'll want more power, facelift has 20 more bhp which will cost you atleast an uprev at over £400 plus maybe an exhaust.
Then there's the facelift headlights. Second hand they're about £800 and well worth it, they look so much better. Also 95% of facelifts have rays, fewer pre 06 have them, there's another £500 you'll want to spend and finally the interior which has better plastics. All this for less than a grand more and £150 ish a year...