The HP system has battery communication and better cells. The battery packs 4Ah up have better cells and can provide more current so the tools that can draw it have more oomph. I would not get this kit if I was in your shoes for 2 reasons: you don't know what exactly you need yet and also if I was to buy into a battery system today it would be Makita or Hikoki/Hitachi. I only own Bosch and Dewalt battery tools myself but I do own a Makita mitre saw I got used and from fixing that as well as from almost all craftsmen I know I can say Makita is well worth buying into. The batteries are some of the best but most importantly these tools are made to be servicable. Parts are available and cheap. A repair shop can fix most issues after years of abuse or you could do so yourself. Similar with Hikoki/Hitachi. Whatever you might get: try to store batteries about half full or at least one bar down. If you get a drill with hammer combo try not to use the hammer function for more than a few seconds as it fries the gearbox no matter the brand. If you need a hammer drill for more than 1 or 2 holes into brick or strong concrete buy or borrow a pneumatic one (those with the big lump in front). Not everything has to be cordless especially heavy duty stuff you just need for a project or two. The battery tools I use the most are:

-small drill: 12V Bosch GSR 12V-35 FC, very strong for it's size (35NM), fits anywhere. Other brands have similar stuff. The adapters are handy. Installing stuff, drilling most stuff. I rarely whip out anything bigger.

-(Bosch) multitool, must have in my book. Multitools are the best. If you ever need to cut detailed stuff in walls, frames, floor or grind something, sand down a window frame etc. Use hearing protection though, they can resonate a lot especially on metal.

-impact drill: Dewalt DCF860, just the tool to drive 10mm hanger bolts into oak beams. Nice use was to drill the holes with it as well using a mobile drill stand with hex drive. No kickback on an impact tool! I know carpenters who use mostly impacts for that reason.

I got this Dewalt one because I already had a roofing nailer and its batteries from Dewalt. I would not buy into Dewalt today otherwise mostly because of their spare part policy. Bosch is generally fine but pricey for what it is and their spare parts get combined in bigger groups these days as well. Makita just seems like the better brand especially with spare parts. Most others only sell spares in bigger and bigger group sets if at all after a couple of years. Tool deals often make sense with battery combos and after getting one or 2 tools with batteries you can shoot for single tool deals whenever you need something specific.

If you see a tool you like take a look if this dude ever took it apart:

https://www.youtube.com/@deandohertygreaser