Well done on the weight loss so far!!
Just buy WPI or WPC, does not matter it's all protein, WPI is more pure and contains less carbs and less Lactose than WPC. I personally prefer WPI and buy it from NoBull, tastes great and is generally delivered the next day after placing your order if you order early enough, and you can pay instantly with PayPal.
http://nobullsupplements.com.au/catalog/Whey_Protein_Isolate-2-1.html
As a basic guide it is recommended that you consume at least 2 grams of protein and 0.85 gram of fat per kilogram of body weight daily while training with weights, this is to ensure that enough protein is available for muscle repair and growth. Not getting enough protein can result in muscle wastage and decreased muscle growth.
Monitor your overall calorie intake, reducing intake if you are gaining too much body fat and increasing intake if you are not growing and recovering adequately between workouts. Calorie requirements will vary from individual to individual, depending on your metabolism, body type, activity level and desired goals in your training.
For fat loss, it is easiest to base your daily calorie requirement on 18 to 29 calories per kilo of body weight per day. Start somewhere in the middle and adjust as needed to achieve your goals
1 gram of protein contains 4 calories
1 gram of fat contains 9 calories
1 gram of carbohydrates contains 4 calories
100gram of whole egg (don't just eat the white as the yoke contains a lot of the goodness and you need the fat, and forget about the old wife's tale of egg yolks being bad for you, as it assist in the reduction of bad cholesterol in your blood) contains about 12-13 grams of protein, 12grams of fat and only 424 mg (less than half a gram) of cholesterol, while 30 grams of WPI contains about 29 grams of protein.