Com Group System - replacing using excel/google docs with SQL?

We want to spec and build a multiple user system, that allows us to replace current google and excel sheets. The system will allow us to enter work recd, under multiple fields, assign engineers to the work, produce reports based on client, dates, engineers etc. the system will allow us to update completed work and track through to finance. we use sage for our invoicing at some stage would like to integrate that. Would like the system/database to be web based so can be accessed on mobile. once we have the core system we have varius add on we like to spec to create a bespoke system