Just been to see a band for the 2nd time to see if we still liked them. (we do) Took mil2b with us. She liked them but as usual was constantly on about money.
She asked about florist and I stupidly told her about the florist i'd found going bust. She'd previously suggested a florist which i'd not chosen. i told her i had a second choice florist but also another one to look at v locally. She asked if i'd been to see 'her' florist and i said no. she got annoyed that i hadn't and said ' well it wouldn't hurt to have a look. (Kiz always does what she says).
She also got annoyed when we spoke about the guest list. We can have 150 people, I have 50, we have 50 and he has 50 which i thought was fair. we agreed on this after his guest list came to 137!! I told him if he insisted on inviting all of his family he would have to cut some +1s, she said 'we'll have to see what we can do about that!' I'm pretty sure that because i don't have any family i'm expected to give up my guests for his family which is bl00dy well not happening.

You choose your own florist, at the end of the day you need to be happy with the decision. Is her recommended florist a friend or one she uses regularly that could offer a discount? or why not task her with getting some info from her florist so you can compare it with the ones you see? Could keep her occupied for a bit ;)
with regards to your numbers, stick to what you've agreed. Ask your h2b to do a list A and B. List A for his most important 50 and B for everyone else. Offer to him that if you have any spare seats after you've received your RSVP's then you 'may' offer them to his side (that is if you've not got a list B yourself) xx