BIG UPDATE
I have finally sorted out what I will use in the SPC_PA sound file, which contains all of the spoken phrases by the hero in the game. I will use banks 5, 6, and 15, and if needed, parts of banks 3 and 4. If I don't use banks 3 and 4, this will make a grand total of 645 sentences per character, which is far better than the whole SPC_PA file which is composed of 4000 sentences and 20 banks, the majority of which not being used during regular gameplay on a 100% completed save.
Please note that if you are still willing to be part of the mod, I just acquired more characters for eventual people who wish to.
List of characters
Akyu, Alice, Aya
Chen, Cirno
Daiyousei
Eirin
Flandre
Iku
Kaguya, Kanako, Keine*, Kisume**, Koakuma, Kogasa, Koishi, Komachi
Lily***, Lunasa, Lyrica
Maribel, Marisa, Meiling, Merlin, Mokou, Momizi
Nitori
Orin
Parsee, Patchouli
Ran, Reimu, Reisen, Remilia, Renko, Rinnosuke, Rumia
Sakuya, Sanae, Satori, Shinki, Shizuha, Sikieiki, Suika
Tenshi, Tewi, Tokiko
Utsuho
Wriggle
Yamame, Youmu, Yuka, Yukari, Yuugi, Yuyuko
*Has 2 forms, regular and EX
**Has 2 forms, on foot and in bucket
***Lily White and Lily Black
Crossed in red: Taken by someone
Crossed in blue: Character is not available anymore for download
In green: Newly acquired