Group texting numbers

I am looking in to buying a mobile phone to communicate with all the members of a club by text. I wanted to know how many people could be included on a group text message. I emailed a mobile phone provider who did some testing on a couple of phones for me and said that it depended on the type of phone. A Samsung could handle about 20 and a Sony Ericsson could handle about 30. Can anyone beat this? I want a phone that can handle as many as possible.

Thank you for your help