You can also use "apt-cache search --names-only BLAHFASEL". This will only search in the package name, not in the package descriptions as well.
You don't need to install everything by itself, e.g. this ...
apt-get install libsamplerate0
apt-get install libsamplerate0-dev
... isn't necessary. Just entering the second is enought, because all -dev packages (needed for people that like to compile stuff by themselves) also loads the normal library.
Also, apt-get ist a bit slow to start, so you can make loooooooong apt-get line with all of the above. But actually "apt-get install fldigi fldigi-dev" should load all stuff that is needed. Didn't you try that? If you got problems, you should post a bug report onto either Mint, or Ubuntu (mint's base distribution) or Debian (Ubuntu's base distribution, which I happen to use).
Another trick that I sometimes us is "apt-get build-deb fldigi". This should always work, because the package-autobuilders of the distributions also use that.