Events company Management Software

I'm in need of a software solution for my Event Design and Management company. This software should manage all company activities,

The software for managing an event design and organization company should include:

Inventory Management
Decoration Production Workshop and Production Costs
Sales
Purchasing
Expenses
Employee Management and Payroll
check list for all stages
mobile application for tracing all activity

The project will be completed in two phases:

Phase 1: Analysis and complete screen design for the software (screen design only).
Phase 2: Full implementation of the software.
Only experienced professionals are requested to submit their proposals.