You're referring to the "Frenetico Tournaments", right? The tournament mentioned by Luna & Gracie at the end of the beach prison event (and they specifically say MC will have to participate if he wants to increase his ranks & prizes are either tons of money or rare weapons).
That tournament will be coming (Hopes said). It's only a matter of time I suppose.
Luna could just set MC up with TJ the gunsmith, her weapons contact (whom she went to meet with MC at Musala hill).
Hope's originally didn't have any plans for that character, but after I asked him about TJ, he said he might consider it (so fingers crossed).
Guess only problem is TJ's guns & the modifications he does to them aren't actually legal (as Luna said. Come to think of it, why am I getting a sneaking feeling that none of Luna's guns are legal

?), so if MC gets caught by the cops (or detectives whom will appear later down the line) when using them, then "busted".

Also, this is just my opinion, but a weapon MC can possibly obtain much later which might be a family heirloom (from his mom Rina) could actually be pretty cool too (weapon which gives off an aura like Witcher 3's Aerondight silver sword but in DeLuca mafia style, for the late to Endgame gameplay).