new stack looks good mate
ON make the best quality powder IMO and
NO explode i found great for energetic workouts (abit pricey though)
as for gainers, in my experience you're better off getting your carbs from an organic source like fruit or veggies. gainers tend to be loaded with sugars which can be useful for an insulin spike after a workout but are otherwise just empty calories. Alot of gainers tend to skimp on the protein and overload with other crap
that said if you do want the extra calories for size then ON would be a good choice and i dunno if you guys have body science in the US but they make good gainers too
:)