http://servman.com/I have developed hooks into their API in the past. Good people and if something doesn't exist you need they will work with you. They are geared toward service companies specifically, I have 6 customers who use this and love it.
http://www.desco-soft.com/This isn't an all in one but they do the service side pretty well and can hook 3rd party apps. The UI hasn't changed much over the last 8 years but the platform works.
http://www.bellasolutions.com/I have a customer I am developing hooks for with this next week. I have been playing with a fully licensed demo for about 3 weeks and this is a good piece of software. The UI looks like a hipster bloodbath but the software is functional with a short learning curve.
I deal a fair amount in the software side and have had my hands on a bunch of this stuff, if you have something specific you have been looking at PM me and I will share some notes and gotchas. I can also reach out to customers and see how they feel about living in a specific software and have them share their thoughts. This is a pretty important decision for a new company and not something you want to have to do too many times.
