A lambs tongue is a way of ending a flat bar railing. Never seen one in
pipe.
Never heard of a rams horn- but I guess its some sort of bent pipe that
ends the railing.

If you want to buy parts to fit pipe, the main supplier for these parts
is RB Wagner- they sell to all the smaller distributors, like King,
Jansen, and Classic Iron. They make pretty much everything for pipe, in
all kinds of metals and sizes, and will do custom anything you can
think of.
http://www.rbwagner.com/

If you want ornamental iron components, here are a couple of more
companies that stock and sell lots of it.

http://www.classicirononline.com/
http://www.jansensupply.com/

Its really not that hard to bend a lot of this stuff yourself, with a
hossfeld bender- which, tooled up, runs from $700 to maybe $2000, but
can be used to bend all kinds of stuff besides just pipe.