System redevelopment, php

We have a system built in php which is basically a very simple CRM system with a few other little features. This system has been built in house and it is being used by several customers but it is time for a revamp. The reason being is that the code over time has become messy with things being added all the time. Also we believe it can be presented better and work in a smoother fashion. One thing that is built into it is to allow for multiple companies to login to the same system and only work with there own data. this however is not used properly so the new system would need to have this working properly I'm an able to show you it currently but, I can safely day it would not take longer that 3 weeks to revamp the system from the ground up. We are looking for someone to do this in a professional manner with flawless coding. This technically could turn into a long term project / partnership. We are open to individual/companies to bid, we don't care as long as the work is professional. As we have developed this software in house we are aware of the costs to redo it all so please do not bid crazy prices as I know roughly 3 weeks work should be. I'l show good candidates the system so they can refine their quotes. At the end of the day this is all simple php builit around a VERY simple CRM, and yes the CRM has to be built. Here is a list of thing that the system must have. Simple CRM - Add Edit Delete clients - Add notes to clients - Task calendar - Events Commission processing from sales imputted. etc etc you get the idea... there are a few other features but again they are very standard php coding. We have had the idea of using a system like Vtiger and adding our unique features to it, but the issue is the multi use of companies. Look forward to working with you.