It is absolutely your choice. They don't get a say. You could give birth standing on your head if you wanted and they'd have to attend and support you.
Personally, I'd highly recommend putting things about your water birth and other wishes into your birth plan and wording them very strongly and also contacting the Supervisor of Midwives at your maternity unit to let them know your plans for a water birth and to inform them of the bs their midwives are speaking. You may not feel it will make any difference to you (thankfully, you have a supportive partner), but it might make a great deal of difference to the next woman they say that to (and who might not have the balls to say anything). You can find out the SOM by calling the non-emergency number on the front of your notes. Just a phone chat or email might suffice, but it's never bad to have a face to face meeting about your birth plan either. I met with one of the head midwives ahead of my birth to go over my birth plan (not because anything was wrong, but just because it's how they do it) and it was very helpful to tell them my expectations and get an idea of any issues they had concerns about (so it wasn't a surprise at my birth!). We still disagreed on some things, but I'm glad we didn't have to discuss that disagreement while I was in labour.
As for a birth pool, is there a home birth group near you? I got mine on loan for 40 quid from my local home birth group. Also, the Home Birthers and Hopefuls group (that is part of BnB but mainly on Facebook, search for them) was getting some pools to loan out, so you might want to check to see if they have them available yet. Otherwise, there's lots of people on there who bought pools and would probably be more than happy to let you borrow it if you ask.
