I love the game and would advise to buy everything they've got. Some creators are good about uploading NO DLC and w/ DLC versions of their wrestlers, but you will be limited if you don't have all the DLC.
You can download just about everyone in AEW/WWE/wrestling history, and most are incredible likenesses. You can download all the individual elements of rings (aprons, mat, posts, turnbuckle pads, etc) then have to assemble the rings yourself (rope & mat colour, etc). Titles you have to make yourself, and where there are somewhat limited options they will be the least accurate of all the custom elements.
I've got a Fire Promoter campaign going as AEW, up against Raw, Smackdown, NXT, NJPW, Lucha Underground, NXT UK, MLW, NWA, ROH, Stardom and 205 Live and having all the custom logos, factions, and a bunch of authentic theme songs makes a world of difference. I still have an n64 w/ No Mercy hooked up to a perfect CRT TV and Fire Pro World is easily the greatest (wrestling) game ever. Probably too good, it can be quite a time sink.