Field Management Software

I am currently looking for Field Management Software for an IT/Telecom business, but I am having trouble finding a solution that meets my needs. The company handles service calls nationwide and contracts jobs through local technicians in the areas they need to serve. So far the FMS I’ve found seem geared towards businesses where a.) all of the technicians work out of a centralized office where each is assigned a number of jobs per day and/or b.) all of the technicians have access to a smartphone or tablet. I’m looking for software that:

1. Is web based (and can possibly be integrated with the company’s new website that will be launching soon)

2. Will allow the central office to input a job (QuickBooks integration for this would be a plus) with details of where the job is, the technician who has accepted the job and instructions about what is to be done.

3. Allow the field tech to sign in from any internet location (computer, phone, tablet) to enter information into a job completion form.

4. Let the manager at a job site virtually sign off on the virtual completion form as proof of work

5. Allow both my business and the manager of various job sites to view a detailed work history of jobs that have been performed for that company.

One deal breaker that I have seen with a couple of the FMS is that they charge a separate fee per technician who would be logging in to the system. Since some techs may complete dozens of jobs for us, while others may be used only once or twice a year, it is not logical to pay a monthly fee for a tech who may or may not do any jobs for us during a stretch of time.

If anyone has any experience with and/or knowledge of a software solution that may meet my needs I’d really appreciate some suggestions.