I had the exact same Eko bass and used this pickup, the K&K pure floating bridge which slots neatly under the bridge. http://www.jp-guitars.co.uk/sales/pickups_and_amplification/kandk_acoustic_guitar_pickups_archtop.htm
As a word of warning, I found feedback to be an issue at higher volumes. This can be dealt with by getting a cover made for the sound hole or by putting something inside the body that stops the top resonating so much (eg, a blow up beach ball, that's not a joke by the way). Feedback won't be an issue at low volumes, it all depends what you intend to use the bass for. Check out this old thread http://basschat.co.uk/topic/146036-are-acoustic-basses-especially-feedback-prone/page__p__1306035__hl__eko__fromsearch__1#entry1306035