Bruce,
I have been involved in similar discussions recently. I assume, from your citing a 74 front blade, that you are looking at a mid frame John Deere tractor (4310 I think you mentioned). I live in Western NC and we do get a fair amount of snow generally, just not this year -- so far. I have a loader mounted front blade for my tractor and in the two snows we have had, it works great. I have used rear mounted blades in the past (and even have one now for grading) but would no longer consider it after trying my new boom mounted blade for snow removal. I assume you would also want a loader for your new machine. With your current request, you would have to remove the loader to put either of the attachments on. While several of my Northeast friends espouse the benefits of snowblowers, it seems one would have to have A LOT of snow on a regular basis to make one financially worthwhile. One alternative suggestion is to get a front end loader for your new tractor, outfit it with a front mounted blade, and buy a rear mounted aftermarket blower for those few times you may need one. You could, in theory, even run both the blade and blower simultaneously (of course not at once, that would be impossible). I have seen the standard 74 front blade for the John Deere tractors and my impression was it was not as easy to install and offered less flexibility than the boom mounted blade. My blade literally takes less than five minutes to install and works really well. It also lifts much higher, is easier to see because it sits further in front of the tractor and can be angled in multiple planes due to its being mounted on the loader arms. Although we have not gotten heavy snow this year, I see that it would take a tremendous amount of snowfall over a short time to make a blower more effective. In those rare instances maybe a rear blower would be your best option, in spite of their need to be used in reverse. I know the JD 59" front blowers are very pricey, unless you could find a used one. In the aftermath of the Blizzard 2005 in the NE, many people are reconsidering their snow removal options, but the reality is that snowfall, on average, is down in many areas, and one must consider attachments that have year round capability. I would be concerned that you could not purchase a 74 front blade and 59 snowblower for much less than you could a 300x or better loader with boom mounted blade AND rear mounted snow blower. I realize you have "decided" on the 59 snow blower, but consider these alternatives. These facts are independent of your main concern, mounting and dismounting times, which would definitely be some slower.
John M.