Cool, I'm glad that 'BeanFarm' is available for you- funny name for a reptile supplier, isn't it? I suspect the land they bought was originally a farm. I've bought from both of those companies- both are good.
Re your drawings- yes, roughly (assuming the tape is going under the tubs). You can search various rack systems to see how they do it- as I said, I don't use them & never have- BUT you want to make sure the tubs aren't sliding right ON the heat tapes- it should be recessed a little where they are installed to prevent that, & also for the minimal REQUIRED air gap (for safety)- as I said, thoroughly read the installation instructions for Flexwatt etc.- & then read them again.Proper design is always better than fixing stuff later. (Inadequate air gap can cause heat tapes to fail from overheating- which is also dangerous!)
I've never used a heat cable sold for reptile use- depending on brands, the ones sold for plumbing purposes might (?) be higher quality, but there may also be important design differences too? I've only used a cable for plumbing, & only for one custom enclosure- never had an issue. They come in various lengths & wattages. READ the specs.![]()