Even a sinner doesn't have an overly loose low end. Strats with "normal" single coils aren't known to be boomy.
But I agree, strats can sound weirdly splatty under gain, because of the very strong treble and attack, without much mid range.
You might find an EQ pedal will allow you to shape the response as you like and give you a load of boost too.
Telerocker: I'll check out that pedal!