(OpneSource) CRM for small businesses. What are options?

##advice Needed from experienced people in IT/Sales who have worked on CRM.

Here is a thing – I am helping a small business owner (out of friendship) with getting sort of online system which can do atleast below 3 points –

1. inventory management
2. quotation generation
3. billing system.

The business is of mainly supplying electircal equipments to various companies (1 govt and many pvt). CRM kind of makes sense. (Its been a long I have worked with CRM (Customer relationship management) systems. Many Many years back I have dealt with Sugar-CRM from installation & administration POV. Don't recall a thing now :D)

1. Can someone reccomend me a good hosted/cloud solution (OPEN SOURCE preffered) / system that will take care of atleast 3 expected function. I am trying to remain in FREE ZONE or with little cost. Important thing is – customization/configuration for this CRM should be easy to done after setup (without any coding experiece).
2. I have studied zoho CRM. The free version looks cool. But I don't think zoho offers quotes/bill/inventory in FREE version. Can someone please confirm if it does offer?
3. The other option I am mulling – singup for google workpsace (and install some CRM from workspace marketplace and see if that helps. Zoho free version is integrated with google workspace as well). Even with 1 user (email) it will cost me 210/month + domain (yearly) + Marketplace vendor fee (if any)

Feel free to suggest anythign you have in mind. Hosted cloud based is preffered, but if there if some good on premise opensource option…that can work as well.