Hi Alex,
to IIS, mate.
First thing to ask is how much do you want to spend? Unfortunately quality means $$$.
Still, there are some good options. I've been looking for them too for my dob. Here are a few ideas I've found:
1: TMB Paragon 30mm & 40mm. Had a fang of the 40mm in my f/4.5 17.5" dob, bloody unreal! Really, really good. Looking at getting one for myself now. Around $300 from Frontier Optics.
2: Agena Super View 32mm 70 degree. Identical to the Orion Q70 & a couple of others. Modest price and not too expensive, though shy of the TMB in quality. About $AU120 imported from the USA.
3: GSO 15mm Super View 68 degree. Surprisingly good in my dob. No discernable coma and very inexpensive, around $50 from Andrews.
4: Meade series 5000 Plossl 5.5mm. My latest EP. Ohh, do I like it or what. Nice eye relief, brilliant image, relatively inexpensive new from Bintel, $130.