Clean up hacked joomla site

I have a small business website I built with joomla. It got hacked recently. The admin file was deleted and an index.html "calling card" was left.
My host asked me to clean it up. I have temporarily suspended the account as a precaution.

I would like an audit performed to ensure no data was lost, that any backdoors and other exploits left by the intruders
are closed.

I would also need a log of what was done for my records.

Forgive me but I am new to people per hour so not sure if anyone can perform this service.

What has been done so far:

I uploaded a backed up version of the administrator file and got my front end website back. The back end administrator page displays but the hacker must have changed login passwords as my login details are invalid. I can probably retrieve passwords however I want to be sure the site is clean.

I have changed my ftp and web host passwords.

It's a site that makes virtually no money so the budget is very low for this. Sorry.

About me.
I help people with small sites but lack the time in putting them together. I work with html and css and fairly new to joomla.
I would like to increase my workload by building long lasting relationships with people who can add functionality to sites, design from scratch and deal with ongoing issues/additions.
This will free up my time to find more work.

Thanks