According to the Fiqh of sayed Ali al Sistani Salat al Jummah behind an imam of the Sunni brothers does not suffice for Salat al dhuhr. In order to not cause Fitna and seemas I don’t want to pray behind them and I only pray when I lead, am I allowed to pray dhuhr before hand and then preform the Salat al Jummah with them after I preform dhuhr?

Yes you can pray Dhuhr before hand