From what I’ve read from people running with street scum, is that it really discourages Street Samurai and decker builds, because both of those are generally dependent on high amounts of nuyen. You just can’t get a useful deck (maybe any deck?) with street scum builds, and attempts at a Sam are very limited because they can’t afford some of the signature Sam ‘ware (like blazing fast wired reflexes or high end cyberlimbs) but also because of the lower limit on gear availability also blocking off some cheaper but hard to get gear. Basically under RAW street scum rules deckers are pretty much impossible but technomancers are fine, a watered down Sam is possible but adepts are more powerful. The natural result tends to be a mix of magicians, adepts, and technomancers.
I think using the street scum rules would be fun (constraints breed creativity!), but be aware of the impact that they impose on the likely mix of characters. Granted -- this is all just from what I’ve read here on the forums, and sometimes forums exaggerate things because people report the ‘odd’ parts and not the ‘normal’ parts.
One thing to note about the street scum build, which I think plays in well with what you are looking at, is a change in the available gear (beyond affordability). Standard 5e build has max rating 6, max availability 12, while 5e Street Scum rule has max rating 4, max availability 10. This doesn’t have a huge impact, but it does block off APDS ammo and a few weapons, limits fake IDs and licenses to rating three (due to availability of 3x rating), puts a couple of commlinks out of reach, prevents the building of really loaded up vision and audio devices, and blocks off some cyberware (or grades of cyberware) that would probably not be affordable anyway. Dropping maximum availability to something like 6 would start to have more impact – weapons are available in every category, but a much more limited selection, it would limit fake ID and licenses to rating 2 which won’t get you into anywhere at all secure, it knocks off a lot more ‘ware, etc. I think that could be one way to get that ‘you are street scum, without fancy toys’ feel. (although what you or anyone else thinks of that heavy limit on available gear, I don’t know)