When to start building? What to use?

mltechz

Background : I've been using MFP with great success for the past three weeks. I've hit my goals consistently. Losing 1.5lbs a week roughly. I spend 60 minutes in the gym 6 days a week. I realize that may seem excessive but I recover quickly and I'm eating right. My calorie goal is 1550 a day and I allow myself to eat the extra calories I gain from the gym if I want (550). I rarely eat more then 300 though and feel full. My goal weight is 165 (started 181, now 174). I'm 5'7 and 43 years old.

Next: once I get to a healthier weight of about 170, I want to try and start building more muscle. I don't want to be huge but my goal is to have a lean muscle physique that's manageable with a 5 day a week gym visit and 1700 calorie diet, roughly.

So what should I be looking at supplement wise? Whey protein? Or some other builder ?