Not to sure on the draper but I can tell you that we run a 30 foot rigid head and can run as fast as the machine will take it in most of the time. If the wheat is to thick though, it will have problems feeding in and will start piling up on the feederhouse, something that a draper should help with. A draper is a lot heavier than the rigid and probably 3-4 times as expensive brand new.
Not sure if a stipper head would be a good choice unless you have fairly level ground. They require you to run as fast as you can to keep it full otherwise you will loose a lot of material before it enters the feederhouse. We do have a guy here that runs a shelbourne on a 2188 and seems to be doing good with it.