Hi Ian,
Good Choice
I asked the very same question and was advised by Andy to follow the OTS Route

. Very, Very good advice on his part, and I have no regrets, so far the software has worked flawlessly, is very easy to use, and the search facility is excellent. It's also very DJ Friendly, has loads of features and runs very stable.
I must admit that I don't have much experience of any other software other than running a few demo versions before ADS pointed me towards OTS.
The only drawback is the price

- but, if it falls within your budget then its well worth the money and taking a look.
Have a look at their website:-
OTS LABSEvery D.J has their own opinions and favourites when it comes to software and D.J'ing. But I'm happy with OTS and it does everything I need it to do.