Get a copy of "Pocket Guide to Low Sodium Foods" by Bobbie Mostyn.  This
book has lists of various foods that are low in sodium.  Most of the brands
of bread that she lists have 60-100mg of sodium per slice.  A couple
national brands listed are Pepperidge Farms Whole Wheat Thin Slice (95mg)
and Wonder 100% Whole Wheat (90mg).

A good recipe book to purchase is the Low Salt Cookbook from the American
Heart Association.  It has several recipes for bread that have as low as 8
mg. of sodium per slice.   The book has the recipes for bread machines too.
Since you say you cannot stand for long, you may find a bread machine useful
if you want to make your own bread. The recipes are in nice large type, one
per page.

If you want to try something besides plain white or whole wheat bread, you
may like rye bread with some caraway seeds and rosemary.

I have the sodium problem too; so post if you want additional information.