K.P.
As far as pumping goes...what worked for me was to have my son nurse on one side while I pumped the other. that way my body would actually let down. Otherwise I could have pumped for hours and gotten nothing but a couple of ounces and really sore nipples. :)
I wanted to also say that I know someone who's baby wouldn't take a bottle--ever. they tried but he just wouldn't take to it. She worked 40 hrs a wk and her husband took care of the kids while she worked. Her baby was perfectly healthy. He just nursed all night long. The way that I see it is that it's no difference than nursing all day long and sleeping all through the night.
I'd say that you can leave the bottle with the sitter and see how it goes. I wouldn't be gone all night long. But, he can handle a few hours without the breast. It's not like your doing this often. Not to mention...I hear that babies are less apt to take a bottle from their Mom, just because they know that they can get the real thing instead (they know what's better--they need that skin on skin contact)
Also- have you tried different types of bottles? I just looked up one that might help you...
just copy and paste.....
http://www.onestepahead.com/catalog/product.jsp?productId...
or
http://www.onestepahead.com/catalog/product.jsp?productId...
I hope one of these help. good luck!