South east london venue - help!

Hi everyone,


I have recently got engaged and finding the first steps of planning very overwhelming!! We are looking for a ceremony and meal for 50 and they an evening celebration of 120 ish. I'm struggling to find registry offices that have rooms for that many people. So thinking we may have to look at venues for the day.
I'm interested in 100 barington in Brixton but this is at the very top of our budget.
I wondered if anyone had any suggestions/ideas/experience with similar area.
Thank you so much