Performance Appraisal Method Suitable For An Mid Sized IT Co

Hi All,
Iam working in the HR dept of an medium sized IT company(Employee Strength-70-100 employees),we were follwoing Graphic Rating method for appraisal but now I want to move over to modern method of apprisal.I have 02 options in mind 360 degree,and MBO
Again I have scratchted out 360 degree since i believe its practiccaly very difficult to administer and have finalised on MBO.
Can you tell me did i make the right decision:
Also it would be grt if you can help with with some MBO formats that we can use for IT sector employees---
Thanks,
Prathiba

May be you shall try Greytip's Appraisal tool. Recently, one of my friends, who has been using the tool for the last couple of years, shared excellent opinion on this.
Here is the product details and you may try for your organization