I can't seem to find these at all. Most of the sources have been deleted and it seems no one is willing to re-upload atm.
If anyone could point me in the right direction i would appreciate it!

Also if you happened to know where the movie soundtracks were as well i'd like those too!

You won't find them, unless you download th One Piece Ost Collection from Torrent, but it weights 3.5GB, I just finish downloading them but movie ost 3 Zip File has password protected >.>
And don't know what it is.

Well actually i already found them. I made a thread in anime music about them. I even found all the movies and that new BGM soundtrack. Yeah they were certainly a pain in the but to find since one piece music seems to get deleted very quickly.

I don't have what you ask for but I've got this: One Piece Super Best - 10th Anniversary Edition (2008) ~ 830 MB (FLAC)

It'd be split to two parts and uploaded to HotFile, let me know if you want, I'll start upping it if you want this.

Isn't that just a complication of the collections 1-4?

I dunno. It's a collection of Openings and Endings:

CD1
01. Hiroshi Kitadani - We Are! (Op1)
02. Folder5 - Believe (Op2)
03. The Babystars - Hikari E (Op3)
04. Bon-Bon Blanco - Bon Voyage! (Op4)
05. Boystyle - Kokoro No Chizu (Op5)
06. D-51 - Brand New World (Op6)
07. Straw Hat Pirates - We Are! (Op7)
08. Maki Otsuki - Memories (Ed1)
09. Maki Otsuki - Run! Run! Run! (Ed2)
10. Tomato Cube - Watashi Ga Iru Yo (Ed3)
11. Suitei-Shoujo - Souchinosuke (Ed4)
12. Ai-Sachi - Before Dawn (Ed5)
13. The Kaleidoscope - Fish (Ed6)
14. Takako Uehara - Glory ~kimi Ga Iru Kara~ (Ed7)

CD2
01. Janne Da Arc - Shining Ray (Ed8)
02. Ruppina - Free Will (Ed9)
03. Ruppina - Faith (Ed10)
04. Zz - A To Z (Ed11)
05. Shela - Tsuki To Taiyou (Ed12)
06. Aiko Ikuta - Dreamship (Ed13)
07. Tackey & Tsubasa - Mirai Koukai (Future Voyage) (Ed14)
08. Asia Engineer - Eternal Pose (Ed15)
09. Triplane - Dear Friends (Ed16)
10. Dong Bang Shin Gi - Asu Wa Kurukara (Ed17)
11. Adventure World - Delicatessen (Ed18)
12. Straw Hat Pirates - Oretachi Wa Family (Ed8A) (Ep 128)
13. Chopper - Chopper Man Theme (Bonus Track)
14. Soge King - Soge King Theme (Bonus Track)

It's not split to two parts but actually three parts, the last is only 39,9 MB.

If you do I'll get it in a few days as I have other files with some priority.

I'm not very much into One Piece (because of how large the series is) but the soundtracks' great!