For Higurashi, might I suggest that you use this:
Higurashi - When They Cry COMPLETE
All arcs (1-8), all patches, working.
Fully updated as of - 20th of February 2013.
part 1 - part 2 - part 3 - part 4 - part 5 - part 6
Check the readme.
EDIT: Translation Patches - Tweaking Higurashi Wiki was fairly recently added to the Higurashi tweak site. I personally do not know how good/bad this patch is right now. Supposedly it fixes some grammar and spelling of the MangaGamer translation for the first 1-4 arcs of Higurashi. This patch is currently not in my pack of the game, so if you want to download and use it you can do so with that link. To use it: Extract all of the files to the arc 1-4 game folder.
^ A complete pack of Higurashi I put together! With that you don't need to worry about what patches to use and not use. You get all arcs (1-8) of the game with as many patches applied as possible while keeping it as stable as possible. A small "fix" or two was also made. THIS IS WHAT YOU WANT! If you want to read Higurashi with patches, that is.
That said, to answer your question, check this: Sprite and BG Patches - Tweaking Higurashi Wiki As you can see there is one graphical patch each for arcs 1-4, 5, 6, 7, and 8.
And yes my suggestion is that you read Higurashi no Naku Koro ni. It's fucking awesome. So is the next part of the When They Cry series - Umineko no Naku Koro ni. Read these VNs!
Saya no Uta is a great horror VN. A short one at that. Very atmospheric with awesome music and unique characters. Very good indeed.
999 can be a bit 'worrying' at times as well. Great atmosphere and music, intriguing mystery, nice cast of characters. Written by the same guy (Kotaro Uchikoshi) behind Ever17 - which is an amazing mystery VN that you oughta look into as well. 999 is an NDS VN though so you'll either need to own a real Nintendo DS, or, use an emulator + rom of the game.