When you have had PR for at least one year. In other words, from 30.04.07 .... tomorrow!
Your wife can apply for her PR only after being in the UK for at least 5 years. So as "she arrived from Germany march 2003", it sounds like she can apply for her PR some time in March 2008.
So the scenario could be :-
- Assuming of course you have passed have passed the UK's Citizenship Test, you can apply for Naturalisation as British. If you apply soon there is a very good chance you will be British before the end of 2007.
- In March 2008 your wife applies for her PR.
- Once she has her PR, given that by then she could be married to a British Citizen ... you! .... she can immediately apply for her own Naturalisation as British.
If neither you nor your wife have studied for and passed the Citizenship Test, why not study together? The pass certificate does not expire, and can be used whenever it is needed.