Really, if you're having a budget of 40k, 33gtr would be the perfect model for you as you'll have heaps left and getting 1 of the best example with your budget.
I think series 3 are nice to have but really, most people like them because of the xenons. If you can find a series 1 or 2 in mint condition, by all means get them. Mine's a series 1 with xenon.