Hostels are OK, but I wouldn't recommend Chung King ... if you stay there you're labelling yourself as a cheapskate who adopts the lowest possible standards ... which is fundamentally at odds with picking up sexy chicks ...
and I don't care how nice the place might be inside, if you can't get her past the leering guys in the lobby, you just wasted an evening's hunting.
Hostels are fine - bin there dun that - and you can find very nice ones in a nicer building. CWB has several, or somewhere like Jordan in Kowloon is convenient. Target to find a place around $250-$300 per night, then negotiate down to $200 per night or so.
Best way is to stay there a couple of nights, make friends with the proprietor, THEN announce that you plan to stay for "at least a couple of months" ... he'll give you a great deal. Anything more than 30 room-nights will get you attention in any hotel - just make sure it's agreed that in return for the long-stay commitment they won't change the rate at peak times.
Peak times are an issue: November is busy with trade shows, so rates tend to be highest at the time of some of the most popular trade fairs. Again, negotiate.
If plan to be really full-on, why not take a hotel near WanChai?
check out
www.booking.com, you often get great deals, with some very real hotels for as low as $500 per night from time to time. Just beware that if you make a booking on booking.com, you won't be able to extend at the same rate: you have to find the same rate still being advertised on booking.com and make an additional booking online. Bizarre as that sounds, I found it reassuring that you won't get as low rates even if you ask them with evidence of your current booking!
At around $12k/30 = $400 per night, even the cheapest serviced apartments are a similar price, and a hotel is more of a chick-magnet, with the added plus that as an obvious business-traveller you have an excuse for becoming unavailable later