The choice of MRP is not important, as long as you feel that you are not spending too much money, and most importantly that you actually can stand the taste enough to drink them consistently. Almost every large supplement company makes an MRP, so you may want to experiment with some of them. The best that I have used is by Mass Quantities, and is called Triple Threat 3/60. It is very tasty and also one of more inexpensive ones around. However, it is not prepackaged like myoplex, rather it comes in a 6 lb bucket with a scoop. If a prepackaged shake is what you need, the best that I have had is called Growth Factor X by GEN. It also taste very good, but is a little more expensive(comparable to myoplex deluxe). I found that no matter what I did, I could never really enjoy myoplex, that is why I shopped around. If you like myoplex, stick with it; it is one of the higher quality MRPs on the market. The EAS bars are a good substitute for myoplex if time is a factor.
As far as a cure for the late night munchies, the best bet is to have a low carb protein shake before bed. Try something like Optimum Nutrition 100% Whey Protein powder. You can get a 5 lb tub for about $27, which is very inexpensive. It has 22 g of protein and only 3 grams of carbs per scoop. I prefer the chocolate flavor, although I have heard that the vanilla is good as well. Just mix one or two scoops with water or skim milk(preferably water since milk is fairly high in sugar). This will hopefully not only satisfy your cravings, but will also help mitigate catabolism(muscle metabolism) while you sleep.
With respect to the before and after pictures in the book, I would say that it is possible to obtain results similiar to those portrayed. Depending on where you start from, and how dedicated you are to the system, i.e. do you "cheat" a lot either with the workouts or the diet, really good results are very possible. For me, I went from having very large love handles and no chest or arm definition, to having a visible set of abs, as well as a defined chest and arms. I saw muscles that I did not even know I had, especially my obliques, which became very visible. My biggest advice to you is to keep a detailed log of you workouts and consistently try and improve yourself from week to week. If you stick with the diet as best as you can, and you can lay off late night carbs, you get good if not great results.
If you have any more questions, don't hesitate to ask.
Good Luck.