diesel repair workshop software

we would like to get a cloud based program designed to run our mechanical workshop from multiple computers at the one time for all different levels of staff members, this will include a phone tablet app, with fetchers like job cards, vehicle history, will need to link the financial side with financial software reckon online for the front of office and accounts personal, there is way to many fetchers / requirements to list here and I couldn't even tell you all of them as I'm just a diesel mechanic not a IT guru, so we currently use software called (workshop software) google it and see the sort of thing we are after, it is missing so much and could be so much better, hence why we would like to design our own software that suits our needs so we can run a more efficient business. I have no idea if this is even possible or the cost involved for such a project that's why I'm getting a feel from the experts to see if its worth perusing or not. I believe its a massive undertaking looking at it from a non IT tech background, but for Tech savvy people it could be a breeze.
thanks for your time.