as for retailers, i think you can go to south asia at funan. try to speak to the lady boss. I bought both my 568, 740 from her. so far, she has given me the best price of all the shops i have visited.
rather she has agreed to my offers.
do your homework about the prices first, then lower the price by a little (sounds cheap skate huh!
) and then you ask her if she can match your price. if you pay by cash you'd likely to suceed
for cases, depends on what kind of cases you want, for better cases like vaja and piel frama you can get then DOML (funan 5th floor).
for sync cables and usb chargers, get them from
Kenar Services, cheapest around to the best my knowledge
good luck to your purchases.