I don't know if they carry the brands you want, but you can try these:
Cathay Photo:
COLOUR MANAGEMENT SOLUTIONS, DIGITAL CAMERA BACKS, LARGE FORMAT PRINTERS, PHOTO INKJET PRINTERS, LARGE FORMAT PRINTING SERVICES, LCD PROJECTORS & FILM SCANNERS
Address: Unit #01-05 Peninsula Plaza, 111 North Bridge Road, Singapore 179098
Tel: (65) 6338 7783
Ruby Photo:
3 Coleman Street #01-01/02
The Peninisula Hotel Shopping Complex
Singapore 179804
Tel: (65) 6338 0236