Just look up the weight of each component you wish to use to see if it's in range. I use the indicam.com sled and it can go from about 1 lb to 17 lbs. I love the design of the hd with the fine balance adjustment screws.
I agree with wbrock, in that it depends on the amount of components you're using. I have the 2000 and while it works great on the canon's due to their weight, we had to add weight around the gh2 to make it balance properly. This was strictly with camera and lens. If you're using a small setup, the 1000 would work great, if heavier then consider the 2000.
I opted for the 4000 and glad that I did.... I also bought the steadicam arm and vest. I can tell you that the 5D is a beast to do handheld on anything and your run times will be short.... I also talked to a bunch of pro steadicam guys and they all told me that as hard as a heavier load may be, the better it will fly due to the inertia... So even when I fly with the Gh2 I put on about 2.5 pounds of extra glidecam weight plates and it flies really well...