Low gears at top end?
You mean, like in 3rd gear and going as fast as you can?
If this is the case, then you need to shift up a gear.
The sound and especially the slight jerking is the engine BURSTING IT'S FUCKING SCROTUM trying to keep up with the excessive demands.
Seriously, it's having a hernia!!
SHIFT UP A GEAR!!!!!!!!!
If you don't, your engine will explode.
However, if this is not the case;
The whistling is either your helmet vents (mine does this at higher speeds), some other part of your kit (probably something with a hole in) or a problem with a component. Have a good mechanic check out the replacement parts. You *may* also have a tiny hole in the exhaust as, IIRC, you have custom exhausts, do you not?
However, if the whistling is more like a whine that alters pitch and frequency depending on engine revs, then this is normal. My bike does it and so does the wife's, although she can't hear hers over the BLATTABLATTABLATTA of her own custom pipes!!
The jerky movement is likely an engine problem, ie something too tight, clogged, fouled with foreign particles or not conected properly (maybe related to the whining/whistling too).