Tac 9 is a short build for EMF100 body. It is good and meant for getting close to the opponents. Way easier to crawl and avoiding hitting trees or getting stuck in buildings than with longer barrel and/or silencer.
Pretty light, but still top rail for sights and bottom rail for weapon light.
Here are links links to stuff you need for this build (some links are affiliate):
EMF100 https://www.paintball.shop/markers/paintball-marker/planet-eclipse-emek-emf100-black_22322_23913/
Tac 9 3D-printed body: Use promo code MAGFEDFI10 for -10% off from Tac 9 body or other products in Styrian Custom Paintball webshop: https://www.styriancustompaintball.at/product/15676308/tac-9
Lapco 8” rifled barrel Autococker threads: https://www.lapcopaintball.com/products/ckr-r6-8-mg100-cocker-rifled-8-686-bigshot-assault
Lapco M16/M4 muzzle tip: https://www.paintball.shop/barrels/barrel-accessories/lapco-m4-m16-bird-cage-style-muzzle-black/a-21941/
CF20 magazines https://amzn.to/3EjJKqr
Magazine couplers https://amzn.to/4glWLgB
Check out some videos with Tac 9 gameplay: