I’m assuming that was you who texted me. For a forward grip, check out the Magpul RVG which is a good, cheap piece. I have one that I’m not using yet, but I planned on putting it on a new upper I’d be building. Check out joeboboutfitters.com for stuff.
Optics there’s such a huge price range and personal preference involved. You’d really have to think about what your purpose for the rifle is when choosing an optic.
For a .40 rifle, check out the Hi-Point if you want something cheap. There’s other options out there, but the problem with most is that there’s no pre-ban magazine options out there unless it takes a pistol or UZI mag that was around before the 1994 AWB. The options are out there though.