We're hoping for between 80 and 150, so it's not that big, but it's more than just an informal afternoon gathering. I'd not heard of EventBrite - thanks - but

We're hoping for between 80 and 150, so it's not that big, but it's more than just an informal afternoon gathering. I'd not heard of EventBrite - thanks - but I've been unable to find an equivalent in the UK. I'd be reluctant to go via a USA company, simply for simplicity. There's probably no reason for that opinion though, and I'll certainly be suggesting it to the other organisers as something to consider.