Web based Help Desk?

Planning a Help desk for 650 users.

Planning on using Kixtart and creating my own web based help system with user being able to check status etc using ASP. I have seen web some web based help solutions but they have no user interaction or can’t modify without suitcase of money.

Also will probably go with Belarc for inventory management.

Any comments or Advice/suggestions will be totally appreciated.

Thanks,
Any comments on