I think you are going to have a hard time achieving what you are trying to do with the tools you are describing. Espresso is a very specific brewing method that produces a very specific type of coffee. Trying to mimic that flavor profile with other brew methods will generally fall short. Using more coffee for stronger flavor is one option, but it ends up not being cost effective in the long run. More extraction is an option, but over extracted coffee often has a flavor profile associated with it that isn't desirable as well.
The closest you can get (in my opinion) on a budget is probably an Aeropress. It is fairly inexpensive and makes a very strong cup of coffee using a reasonable amount of grounds that isn't espresso, but also isn't over extracted. The downside is that it's difficult to generate crema with such a brew method.
You might be forced to figure out which aspects of the long black you like, then come up with a brew method that gets you close on those aspects, but is probably missing others that make up the true long black.