Current state of the world as of this post:
1)Any new build from Fremont or Austin will have HW4....you would have to find a very old build (May for Fremont, June for Austin) to get HW3.
2)Fremont will have Matrix lights. Austin will have non-matrix lights.
3)If you transfer FSD, buy FSD, subscribe to FSD or get a 3 month trial of FSD on a new HW4 car you won't have access to FSD Beta. You will only have access to regular FSD which is EAP features plus the ability for the car to stop at red lights and stop signs.
All new cars ship with base FW that includes FSD Beta version 11.3.6 which doesn't work on HW4. FSD Beta version 11.4.X works on HW4 but is being kept back on an old base FW (2023.7.X). The only people that have 11.4.X are employees and early beta testers (influencers) but only a few of those have it on a HW4 car because most influencers have HW3 cars. Only when Tesla releases a base FW greater than 11.26.8 that also includes FSD Beta 11.4.X or higher will the new purchasers of FSD on HW4 cars get access to FSDBeta. If you are on a free 3 month trial your trial may well run out before that happens. You will be able to try out the EAP and FSD (non-beta) features but not FSDBeta (ie Navigate on City Streets).