Hi Xavier, there are lierally hundreds of options. Red dots, scopes, you name it. As long as it will mount to a picatinny rail, you can put it on. For fore grips, just get one that is MLOK compatible, or use a MLOK to picatinny adapter.
Stay safe & have a great day!

There's also the Sig Red Dot/Magnifier combo. I prefer my optic with the magnifier for distance shooting.
budsgunshop.com/product_info.php/products_id/103856/sig+sauer+electro-optics+sorj53101+romeo5+combo+3x+20mm+obj+2+moa+red+dot+black+cr2032+lithium+2 />I like the Magpul angled firegrip.
budsgunshop.com/product_info.php/products_id/10290/magpul+mag411-odg+afg+angled+fore+grip+ar+platform+od+green+polymer

Hi Xavier and welcome. The Romeo is a popular option : budsgunshop.com/product_info.php/products_id/6997/sig+sauer+electro-optics+sor52001+romeo5+1x+20mm+obj+unlimited+eye+relief+2+moa ------------- and MLOK Slim fore grip : budsgunshop.com/product_info.php/products_id/723006807/leapers+inc.+utg+super+slim+vertical+foregrip+m-lok --------------- or angled fore grip : budsgunshop.com/product_info.php/products_id/714022816/utg+ultra-slim+angl+foregrip+mlok --------- Cheers and stay safe!