Your chances of getting employed are going to be better with 700 hours than 250 hours. I would say the recruitment boom of 2007 is now starting to decline.
I wouldn't set a time limit I would say instruct until you hit 650 to 700 hours total time then do the IR. If you do the IR then instruct it is likely that you will have to do another renewal before getting a flying job somewhere. You will easily aquire these hours within a year of full time instructing at a busy school so no problems with the 36 month limit on the exams.
I am not sure on your financial state but if you taking out any loans to fund training then it is easier to live on instructors wages if you haven't got to make rapayments on a loan used to fund the IR.
Last edited by portsharbourflyer; 3rd May 2008 at 10:32.