I'd go with a PPC ad system rather than CPM for your level of traffic, CPM I'd say for 10K+ per day, 1-2K is probably better off using PPC.
use openx markit its much better from epom .. i am using from 1 year and i get ecpm around 0.70 , 0.80 and they always send payment on time..
why don't u try edomz ?? They are preetty good in terms of rates .. if u have a huge traffic & it's from serch engine.. you can get 2-5$ ecpm
That's how I feel, I hate popups/popunders myself so wouldn't put those sorts of ads on my sites for my visitors either.
if you really think popup and popunder are annoying then you would also want to stay away from a lot of cpm network which are just crap and show hidden ads, redirects and even has popup ads even if they called themself so called cpm network they show multiple pop and redirect pages I would prefer good popu instead of going with such so called cpm network But if you really don't like pop ads I can understand that then just go with good cpm network like valuclick media etc otherwise will end up even with worse ads