A lot of the long-term 141s do speak basic English, and a few of them are able to go beyond the transactional necessities.
Shirley in SW is one that I do know speaks pretty well. You could try giving her a call, or sending her an SMS, before you come.
Also worth trying any that say her race is "mixed" or "English". It's never 100% true, but a much higher proportion do speak some English for a variety of reasons.
If you want to take an English-speaking girl back to your hotel, actually I think your best bet is to hit the WanChai bars starting around 10pm on Saturday, and aim to be hooked up by 1am (a lot of girls make their choice who to stay out with before the MTR closes). You can hook up for free if you're not too fussy or prefer the feel of the chase

Or if you're clear about your budget and stick to it you can get a good-looking FL.