We are an IT shop as well and use the usual integrated into Sage 100 - Time & Billing for invoicing and Timekeeper for Time Entry. We use CRM for trouble tickets and are just getting started using the Self Service Portal for client ticket entry and tracking.
Is it perfect... no. Is there a few minor things that SWK could fix (Paperless) in Time & Billing... yes. Is it terribly time consuming for monthly billing... no, I just did my monthly invoices in less than 30 minutes. Takes about that long to stuff the envelopes, which would go away if they would just fix Paperless.
There are a few things that could be done to tie Timekeeper into CRM using a VI job. Our guys often complain about duplicate time entry since they typically track everything on their calendar as well. I've ventured down the path of adding fields to CRM Cases that could be used on the import to Timekeeper and streamline that process, but it's kind of faltered a bit and is waiting to be finished. If they would fix a couple things in Timekeeper so the browser based time entry would work better our guys would be much happier and you could probably just tie that piece into a CRM screen.
I've sat through a demo of Autotask and they say they can integrate into Sage100. That will bypass T&B and go straight to SO/AR as a VI/BOI. You would do all your project tracking and management in Autotask. I like to just buy software and hate the monthly fee model, so I'm not a huge fan so far of this solution. It does some very nice things relating to the IT world, but nothing that really just blew our CRM solution out of the water and definitely not for the monthly fee we would be on the hook for forever.
It all comes down to the accounting for us really and it sounds like it probably is for them as well. You still need to collect the money and pay the bills, no matter how much the IT guys want to whine about how dated their T&B screen is.