ITEAD GPS shield Buffer Size needed

hi all, I have Itead GPS shield and I want to know What Buffer Size do I need to Get Full data ?? or how much time should I listen to the RX ?? thanx

Why are you not using TinyGPS (or TinyGPS++) to handle reading and parsing the data from the GPS?

I am using it but I think I should set the buffer size of the library , shouldn't I ??
Also I'd Like to ask you what baud rate should I use, I have seen many websites some saying 34800 others 4800 other 9600 what's the correct one??? thanks

Leave the library alone unless it's causing you a problem.

The baud rate you need is whatever your GPS is set to - that may vary by model, hence the variation you see in example code. Note that you can generally tell your GPS what baud rate you would like it it use.

but I think I should set the buffer size of the library , shouldn't I ?

No, and you should not be using two question marks for one question.