Where to find pride wearables for the pride parade?

Some plans got cancelled, and my RPG group now wants to attend the parade. We consist of straight allies including my boyfriend, myself and my best friend, and a gay male couple.

It's not like it's necessary, but we do want to dress in pride gear. None of us really have pride gear as we haven't done the pride parade since college. Since plans were cancelled last minute, we're hoping we can find some things on the fly.

We're all carpooling and plan to shop together on the way to Downtown. We'll be leaving from Eldridge/Westheimer (what do you call this area anyway?).

Any recommendations would be great, especially along the way towards Downtown. Thanks in advance!