Visualization advice for a neo4j rookie: fixed node positions and varied edge thickness

Hello new neo4j friends. First time poster here!

I have a graph set up in neo4j already. It has 40 nodes and around 1000 edges, where many pairs of nodes are joined by multiple edges. I've been looking for a way to visualize this graph in a way that meets the following two specifications:

  1. I would like to choose (and fix) the position of each node
  2. I would like to have the multiple edges between each pair of nodes replaced with a single edge whose thickness corresponds to how many edges there actually are between those nodes.

It is fine (actually preferred) if this is a standalone visualization. That is, it doesn't need to live on a web page or anything.

What visualization tools do you think would work nicely (and as easily as possible for my simple mind) for this application? I've played with neovis.js, but I wasn't able to see how to control the layout of the nodes in order to put them in specific places. I tried downloading and running Gephi, but there seem to be issues with getting it to launch on my laptop.

I would appreciate any advice you might have to offer. Thanks very much!