Sounds like speed won't be important
and none of these will be noticeably different for internet use. Personally, I like an i5 system as good compromise that allows decent performance and some room to improve. I might suggest your #4 choice to be a good start. About all that might be lacking is some graphics performance with videos. I'd see how that goes and add the video card later if you really need it. Adding a video card does come with the possibility of needing a better power supply but I'd hesitate to buy the HP with the dedicated graphics card if it had the same PS as the one without the card. That would tell me it was rather low end anyway.