I would also suggest that you do most of the heavy lifting on the back end. Get some data pipelines setup and cleanse and pre-crunch your data into a solid data model that easy to consume by any reporting/BI tool and reasonably easy to understand by a non-developer analyst. Never point a BI tool at your core transactional operational database (for lots of good reasons) - always replicate the data to a reporting database or data warehouse. This is the harder bit to get right and I would follow a standard data warehouse design patern for this part - although I would not recommend enterprise data warehouse vendors unless you have a massive volume of data and large budget. We have achieved solid solutions using low end SQL databases with Power BI on top.
I personally lean towards Microsoft/Azure as an end to end solution for what we do but the architecture and approach above is agnostic to what vendor/platform you choose.
Hope this helps.
I've been using a lot of these BI tools. Qlikview has a very strong front-end but like said before, comes with a cost, especially if you grow the usage it can become expensive. I would suggest to take a peek into PowerBI, there is a free version available and it connects natively to your SQL DB.