Visiting Gallopoli (Istanbul)

Hi,
We are three Aussies living and working in Kazakhstan, and we are visiting Istanbul at the end of March for a week. We want to go to Galipolli as an overnighter and we want recommendations of where to stay and what is the best way of getting there. We seek comfort in our transportation. We probably seek mid-range accomodation and would pay more for something that is considered "worth it". Any thoughts on this one?
And...any cool markets to recommend in Istanbul.
Laraine