Welcome on board! Monster would definitely be my choice if I was under 6' as I've always loved them. S4R if you can afford it, as it'll keep up with most bikes assuming you can hold on!
And don't believe a word Ruth says, she's actually a cross-dressing 6'8" hairy-chested (so rumor has it...) 996SPS-riding biker called Chuck. She's just very good with make-up.....
Cheers,
Ali