Here is a complete set of 1st WW infantry cap badges. Guards, infantry of the line and some miscellaneous ones (territorial county regiments etc) on the bottom line.
They are just Other Ranks cap badges, not officers.
The listing should tell you which is which - in official order of precedence - and their date of issue.
http://www.britishbadgeforum.com/for...ictureid=58508
Like many boyhood collectors I gave up with cavalry badges as they were too expensive !
good luck anyway