I have a CAAD9 and I'm looking to upgrade from the platform pedals to toe clip or strap pedals. Does anyone have recommendations on the best ones I can get for close to $20 price-wise? And is 9/16" the standard thread diameter?

I'd like to stay away from having to get clip-in pedals and shoes, because I want to be able to get off the bike and walk around. Thanks in advance!