If you want something off the shelf, consider Agfa FX-Universal, a neutral (pH=7.2) ammonium thiosulphate based fixer that is primarily sold for colour processing but is ideal for B+W if you want minimal odour and reasonable price.

They are now packaging it here (Australia) with B+W dilutions for film and paper.

If you want to mix cheaply, sodium thiosulphate and sodium sulphite are all that is really necessary.

To this, you could add ammonium chloride or ammonium sulphate to make it a bit more like rapid fixer.

The other ingredients that are in most formulas are for hardening, including acids. It is acid that makes most fixers smell strongly of SO2.

Have a look at Lloyd Erlick's site for interesting articles (and photos!)