Without posting the specifics of what you want to drink, it's hard to say. I'm not that familiar with FRS as a protein drink - ive seen some bottles in the sports store, but they were full of carbs.
As a brand new post op, when picking your protein shakes you want to focus on a few things -
1 - high protein, low carbs, low cal - for me, I only drank shakes that had less than 5g of carbs in them while I was a new-pre-op. Now, I limit my protein drinks to around 10-12g of carbs, but im further out. You want to watch the fat content (at 9cal per gram, it adds up quick!)
2 - look at the source of protein - you want to stick primarily to whey protein, whey protein isolates. Avoid incomplete/less useful protein sources. I will do egg white protein/soy protein now but it's not my primary source.
3- efficiency - if you find it hard to get in enough fluids as it is, id go with shakes like premier nutrition where you can get 30g of protein in an 110z shake. You dont want to have to drink say - 20-30 oz to get in the same amount of protein if you struggle with it.
www.sexyskinnybitch.wordpress.com - my journey to sexy skinny bitch status
11/16/12 - Got my Body by Sauceda - arms, Bl/BA, LBL, thigh lift.
HW 420/ SW 335 /CW 202 85 lbs lost pre-op / 133 since surgery (lowest weight post op: 188)