First of all, I'd like to warn you: depending where you show and what you show in, you may not be allowed to use certain types of stirrups. For example, the USEF banned the use of black stirrups in any eq ring. Using them would cause elimination. Colored stirrups, though they are fun for schooling, cannot be used in hunters or eq, though you could use them for jumpers. I've always been taught that traditional is best, and it's safe!
Personally, I really like MDC stirrup irons! They have lots of different options to fit your individual needs.
I love my Composite sturrips! They come in fun colors too! https://www.amazon.com/Compositi-Premium-Pads/dp/B007TNRU9U/ref=pd_lpo_vtph_200_lp_img_3/130-3319128-1288616?_encoding=UTF8&refRID=7A9XTM01FAP96Z2YSMYB