If all you want is simple flights why do you need a travel agent? The airlines will give you the same price direct. BA, CX, VS fly non-stop (and QF from November).
CX's best fare to LHR currently is HK$4900 for travel in November; $5500 for other times except Xmas. (These are restricted and non-mileage accruing fares.)
More options including with connections on BA to other UK cities at:
http://www.cathaypacific.com/hk/book...HKG-GB,00.html