Rubber feet that come with the Bipod are fine. There are stages where cleats or spikes would be advantageous and others where they would not. The rubber feet haven’t ever been a major inconvenience for me, though. Start out with the rubber feet and see how they do for you. Then decide if you want to change.
I see you’re trying to gear up for your first match. Don’t do that. Take some simple stuff and see what others have. I’ve never been to a match where people weren’t willing to share their experiences and let you borrow a piece of gear for a stage to see how it works for you. People who have been at this a while have tried a lot of the different things and probably have it all with them, even if they don’t use it anymore. PRS shooters tend to be packrats as long as they can have a vehicle nearby. I would almost guarantee they would be happy the tell you the pros and cons of something, let you see what they have, and show you ways to use it you never thought of.
Take a notebook to the match. It doesn’t have to be anything whiz-bang tactical with a molle cover in multicam, just a plain little notebook. Before the match, write down all the pieces of gear you’re thinking about. Ask some of the guys on your squad about them. Take notes on what gear others use on what type of props. People will use different stuff on a barricade versus a rooftop versus all the other things match directors think up. See what the other guys/girls use for bipods/feet/dope holders/bags etc... Make notes on brands cause typing “flip out card holder thing” in to google may not yield the results you want. See if some gear is redundant. This is important if you’ve got to pack all your stuff from stage to stage.
After the stage, write down what gear you used and how you used it. What gear, real or imagined, may have helped. And how you did. Be honest with yourself. Did you miss because the Bipod was too high/low and you couldn’t get on target? Or was it bad data or wind. You can buy your way up in the sport, but only to a point. Eventually some skill has to be learned.
This sport has tons of gear and it all costs money. The sky is really the limit. See what’s out there and what works before you buy a bunch of stuff. Odds are you will leave that match having seen, or maybe even been allowed to borrow, a piece of gear you didn’t know existed.
Have fun at your first match. Keep a good attitude and learn all you can. Meet as many people as you can. You will begin to see the same people match after match.