Going to do some surf fishing for bull reds in Sept, he’s got a drone so I won’t be casting. I’ve got a 7’10” irod bass swimbait rod I’m thinking about using. I’m looking at buying a Penn Warfare 20 with level wind reel to put on it. Will this be a good setup or would either the rod or reel be overkill for this? If not, what weight mono to braid should I go with and how much of each? I’m a fresh water fisherman, just breaking into the saltwater arena…

I think you will be fine with what you have.
30 feet of 15lb mono backing to 50lb braid main line to a four foot leader of 30lb mono.
You may get lots of different opinions. Here's a previous discussion bullred setup

I like this rig but would go bigger than 15# mono for bull red.

That is asking for breakoff.

Carolina rigged. 30# Fluro mainline and leader is fine.

We use 30# braid with a 3' 80# double drop leader on all our rigs. We plan on going 2 times in September to fish the Matagorda Surf. We catch most of the reds in the first gut so no need for a drone. Take a cast net ,you should be able to catch all the mullet you need in the first gut.