how long should we wait to get a response?
he is a US citizen from birth, no he only sent the I130
Send the rest too!! You'll get EAD so you can work anywhere and AP to travel Plus it'll be faster to get GC, because I-130 and I-485 are done in same time. Now you separate them out and it'll take twice more time.
before advising to file I-485, you should ask if the original poster is in the US. Because if she isn't, she can't file I-485.
do i need to apply for an I131? I already have my british passeport
Double check if visa waiver country's citizens are eligible to file I-485