Richard,
Might I give you my recommendation
I say go for all the globulars. They are the most spectacular (in my opinion) DSO's and can keep you entertained for hours on end (especially since you have an 8" scope which would make easy meat out of the brighter ones). Since you have Omega Centauri, try 47 Tucana (don't know if it is too low at this time of the year though, Tucana near the SMC), NGC 6397 (Ara glob I think), NGC 6752 (Pavo glob I think), M4 (Scorpius), M22 and M55 (Sagittarius), M10 and M12 (Ophiuchus) and M13 in Hercules. There are heaps more in the the last two constellations. Now is a great time to be observing globs!!!!!
Darren