kimevans,
Seat Guru only have a small selection of seat plans, predominantly for major scheduled carriers. As Wizards mentions, we have them linked from our What Aircraft? guide (link below) with lots of other aircraft information. Your flights are operated by a Boeing 767-300/ER, specifically in the former First Choice configuration (currently). Not all extra legroom seats are by the toilets, row 20 / 28 (depending on the aircraft assigned on the day) are by the overwing exits. Tray tables and IFE screens fold out from the arm rest on these rows. Whether the premium upgrade is worth it or not is personal preference. See my comments on
this post. If all you want is more legroom, premium seating might not be worth the extra for you but it really is personal preference.
Darren