Developer learning tools

Hi all,
It's been a while since I last posted a question, and it's not properly
technical this time.

I have been working hard to improve on my technical knowledge of a few
subjects, SQL and Code4i extension for local development to name a couple,
and now to go on with my learning I need a couple of things that I haven't
been able to find yet.

Firstly, a reliable system to set up my environment and do my test. Because
of my consultancy work, I don't have a personal space as I usually work on
the Customer's system. PUB400 is a <<<great!>>> resource though it has
limitations (of course given its public use!) and sometimes it's down when
I have spare time. RZHK, where PUB400 is hosted, offers a developer's
account (meaning: a shared IBM i 7.4 or 7.5 environment with current PTF
levels and IBM software maintenance, the possibility to create your
libraries, and 5GB of storage) at a convenient fee (about 50 euros/month),
anyway, I have unsuccessfully tried for months to reach them.
Here comes my first question: do you know of any other cloud platform
providing such a kind of offer, again at a reasonable fee given that I am
doing it on my own?

Secondly, SQL advanced knowledge. I have found many companies offering SQL
advanced courses whose syllabi include topics such as:

- Identify the impact of Summary Tables, Materialized Query Tables, and
temporary tables
- Use complex subqueries
- Use a greater number of scalar SQL functions
- Use advanced SQL constructs, such as recursive SQL and table
expressions
- Define User-Defined Distinct Types and User-Defined Functions
- Avoid several of the most common causes for poorly-performing SQL

All of those I found relate to DB2 environments, though specifically for
z/OS, Linux, UNIX, and Windows. None of them was for IBM i, and especially
when speaking of performance it can't be this way.
Finally, my second question: do you know of any course of this kind? I can
easily attend it in English.

I have written a lot, I know, but I wanted to be clear about what I am
looking for.

Thank you very much for any hint or suggestion.

Meanwhile, I keep on learning from the online discussions.

Lucia