From limited experience with the existing reclists I'd say CVVC (especially the Lite) but well, again it depends on the person
UtaForum.net
MillyAqualine
HoneyPai
You could always record Delta cvvc English, there are 7 lists, and one list is 270 sounds, or teto's list, it's 290(?) but you can use teto's oto as a base
Nohkara
I think that Delta's list is pretty good. It's 3 mora and pretty straight forward to read once you know how to read "x-sampa"
Nohkara
How to read Delta ENG chart link is here in Delta's blog post: http://sp.ch.nicovideo.jp/delta_kimigatame/blomaga/ar761052
To avoid overwriting, big letters are marked with "+" in recording list. E.g in reclist E is written as "e+". Also, in Delta's reclist @ is a "schwa" sound. I hope that this helped!
To avoid overwriting, big letters are marked with "+" in recording list. E.g in reclist E is written as "e+". Also, in Delta's reclist @ is a "schwa" sound. I hope that this helped!