Hi,
I am a AWS developer and software engineer by profession, who knows a great deal of technology stack including Java/J2EE and related frameworks.
Frankly speaking I have put a bid amount because I am not sure how complex system you are expecting.
If it is just about web based inventory management, then please contact me. I would be able to design a system for you in not more than 20 days.
It will be hosted on AWS under your account. I can also provide support post development till the time you need a support.
Thanks,
Dharmendra