hI D - rye bread without wheat flour is pumpernickel.
Rye bread, to keep it like a normal loaf needs to have wheat flour in it as rye has little gluten, so will not give a fluffy finish as there will be little air in the dough.
If you muck about with sourdough and rye combinations you may get the lighter result, and you can get white rye flour which may also help -
http://www.shipton-mill.com/shop.php will sell you minimum 6kg of a light rye flour online or track downa locla miller - maybe at a farmers' market near you as one option. Graigs Farm and Doves Farm - couple of the 'brands' of organic and 'proper' flour suppliers - don't list a light or white rye, but you could approach them and see if they can suggest a source.
As a suggestion for a recipe,
http://www.preparedpantry.com/americanryebread .htm has a blender recipe for a light rye - but also uses wheat flour...but it does look nice though....