How about either Saturday 11 June or Saturday 25 June?
If people want to go to a Weatherspoons, I suggest The Monk's Retreat - I think it's probably the nicest of the three Weatherspoons in Reading town centre. It's an easy, short (5 mins) walk from the train station. It's next door to the back entrance to Marks & Spencer, so if you get lost, ask anyone to point you in the direction of M&S and you're sure to find it.
In terms of hotels, I'm really phone-phobic, so don't really feel up to ringing round lots of places. I think it will really stress me out. Sorry! I reckon the info is probably all available online but it will be difficult to get an accurate quote without certain info eg date, whether you want to be able to cancel it or are willing to go with non-refundable, whether you want a single or double room, whether you want breakfast included or not etc...
Typically, when I've stayed on a Saturday night without any offers on, Ibis/premier inn/travelodge etc have been around £50+ on a saver rate (ie if you cancel, you won't get a refund) and without breakfast.