I've been waiting for a RGB model myself in the usual price range. I didn't see anything in the description that made clear an analog RGB signal is accepted, though. Somebody has to research more and take the risk in buying one.
I decided to look a little bit deeper and the imputs are on the top connector maybe a simple process of plugging in the correct cables here is the interface plugs and what each one does
Interface
PIN NO. SYMBOL DESCRIPTION
1, 17 3.3V Power positive (3.3V power input)
2, 4 5V Power positive (5V power input)
3, 5, 7, 8, 10, 12, 13, 15, 16 NC NC
6, 9, 14, 20, 25 GND Ground
11 TP_IRQ Touch Panel interrupt, low level while the Touch Panel detects touching
18 LCD_RS Instruction/Data Register selection
19 LCD_SI / TP_SI SPI data input of LCD/Touch Panel
21 TP_SO SPI data output of Touch Panel
22 RST Reset
23 LCD_SCK / TP_SCK SPI clock of LCD/Touch Panel
24 LCD_CS LCD chip selection, low active
26 TP_CS
Touch Panel chip selection, low active
External Dimension
3.5inch-RPi-LCD-A-dimension