we use many different wedges - depending on particular job / end product / timber size etc - i don't think you can have too many wedges.
having said that - my dad has collected old tools all of his life (huge collection) most of our hand tools are 50 plus yrs old - and we probably have 30 or more metal wedges to choose from. we make and use wooden wedges too, for big stuff that needs splitting - once initial split run is in line.
we split most of our cut timber (chestnut) - for a variety of different uses, so having a great choice of splitting tools is very important to us.
why not get yourself to a tool sale - like the one toby has posted about -
http://www.swog.org.uk/forum/viewtopic.php?f=22&p=10263#p10263i expect you'd find a good selection there