IT Services Cost Estimating

Good day to you all.

I have recently looked into setting up my own IT business that specialises in setting up and maintaining IT systems for local businesses.

It is to include initial consultancy to take their needs right the way through with custom configurations and services, up to the general service contract.

Does anyone know of a particular estimating program that will suit my needs well?

Preferably i would like to test some software before i begin spending out money that may be a waste.

Any help in the right direction is as always very much appreciated!

Thanks, Matt