Just my opinions here.
First... think of things in terms of a week. NOT a day. This will give you some leeway in order to budget things accordingly.
1400 calories a day is 9800 calories a week. This is what I did (the strategy, not the numbers). This way, when I would inevitably cave on a particular day, it wasn't blown. In fact, in this last 25 lb that I lost recently, I had days where I went absolutely nuts (pizza, buffet, pizza buffet, etc). Budget that out over a couple of days, still lost weight when I weighed in the following week.
Just my thoughts, I am an engineer, not a nutritionist/personal trainer.
Dropping 5 lb a week on average over the whole 40 lbs is un-reasonable. In my experience (with both myself and my wife), the first 10 lb will fall off at about that rate (2 weeks)... the remaining 30 will come off at roughly 1-2 lb per week.
Eating 5 times a day or 1, or any other number. Doesn't matter. What ever makes you comfortable. I also do not buy that there is any metabolism hit. Let's just say, if there is, I would be in a world of hurt.
As Leaf said: How much is more important than what in terms of eating. There is no strategy out there that will make up for eating too many calories. Even if eating 1 meal a day over the course of an hour.
Personally, I am not a fan of meal replacement stuff. Inevitably, you are going to stop doing the meal replacement thing and go back to eating a meal instead... then what? IMO, change your eating habits and learn to eat meals that will fit within your needs.