We used a mix of cloth and sposies. And we did EC (LJ, since you are trying to be as green as possible, I would encourage you to check out diaperfreebaby.org and the EC forums on mothering. Then you don't even have to wash dipes!)
At the outset, we used prefolds with snappis and covers. My newborn size fit DS to about 4 months or so. My initial stash 24 prefolds, 4 covers, 2 snappis, 2 large wet sacs, 1 small zip up wet sack for my diaper bag) cost less than $80. I also bought the small size prefolds (I think 20 or so) and covers, but ended up selling them because we had DS in trainers at 7 months and I didn't really need them.
We used sposies overnight and on longer outings and car trips (like more than 3 hours). So I used less than 10 sposies per week most weeks. (Keep in mind, the cost of sposies varies depending on where you live, where you buy them, and the size of package you buy. I would wait for the big packs to go on sale at Superstore and then pick one up. If I'd been buying them at the local grocery store they would have cost way more)
With 24 prefolds, I did not have to wash dipes every day. More like every other day.
We started EC when DS was 2.5 mos old. Within a few weeks I was having very few poopy diapers to wash because DS was very predictable about pooping (he communicated it very clearly). By the time he was about 6 mos old, we had almost no poop misses (only on very rare occasion) and by the time DS was 7 mos old we had him in trainers and had about 2 wet trainers per day, and I can count on two hands how many poopy ones I had to wash before DS was potty trained at just shy of 19 months (so if you wanted to use cloth and found EC could work for you, handwashing pee diapers would not be a difficult undertaking!). I sewed the trainers myself, and calculated that they cost me $4 per pair, plus my time. I had about 10 pairs. So that was $40 x 2 (I had to do two sizes as DS grew). We continued to use sposies over night and on long car trips because overnight EC just did not work for us. So again, less than 10 sposies per week (probably just the 7 most weeks).
So, my total cost for cloth was approx. $160 over 1.5 years.
I can do a rough guesstimate at the sposies cost at $.27 each (we used pampers) at 10 diapers per week ~ 78 weeks x 10 diapers x .27 = $210 approximately.
A mix of the two worked best for us.