ok I had a look Lee, you may want to factor any insurance difference as well as the tax, which is as follows;

1.9s tdi 135g £66 for 6 months & £120 per year
2.0 gt tdi 149g same as above
2.0gti petrol 192g £115.50 for 6 months & £210 per year

All set to rise next year!