I've been thinking about converting a couple of html sites to wordpress.

One question - it would be good if I could replicate existing urls without having to redirect everything.

In permalinks I can use something like %category%/%postname%.php which seems like it would work - at least it adds .php on the end OK, but wordpress say 'Starting Permalinks with %category% is strongly not recommended for performance reasons.' They also say the same about tags.

Current urls are all like www.sitename. com/directory/filename. php

Is there a better / different way of achieving the same goal?