first of all: 'english voicebanks' aren't exactly a thing from all i know. there are voicebanks with english sounds instead of japanese ones, sure, but iirc, you still have to type in romaji (usually) or hiragana (sometimes) in order to get those sounds out.
second of all: so do you want english or japanese? if japanese and you just need romaji, you either type in romaji and use a romaji voicebank, or type in romaji and use romakanaswitch/iroiro2.
third of all: i can make a replacement list for iroiro2 with cv romahira conversion if the built in iroiro2 switch/romakanaswitch doesn't work.
lastly, a pro tip: just learn japanese. if that won't do, take other people's usts, look at reclists and just try to understand how japanese sounds work and which ones resemble the english ones most, and, well, use them!
hope i helped, i don't know much but i said what i did know :3
P.S.: i can help you find suitable voice banks if you elaborate on what specifically you need. a cv voicebank that reads romaji and has english sounds? a vcv romaji japanese one?
P.S. 2: if you want to make english talkloids and not songs, it's best to just use romaji and vcv to make it sound at least remotely like english. crossfading, flags and consonant velocity can also help i think.