Jami,
Keep in mind: you can't run a wireless system (or so I was told) because of RFI from the ignition system and you want one that will read up to 100 mph. It is no good to have one that goes up to only 45mph. One more thing,the face on these are normally 1". You will have to practice reading at a postage stamp while you are riding.
If you want I can send you this one to look at before you buy.