Welcome to the forum.
I start all my prints with something along this line.
M190 S115 ; wait for bed temperature to be reached
M104 S235 ; set temperature
G28 ; home all axes
M109 S235 ; wait for temperature to be reached
But I manually set the bed temperature in Repetier (You could use Pronterface to do the same). Wait for the bed temp to almost be reached then start heating up the extruder. Then once they are both are to temp, I run the G-Code. My prints typically start within 20 to 30 seconds of when I drop the G-code.
One tip I have for heating up you bed a little faster is put a pot holder or towel over you bed while warming up. Save me a lot of time.
Here is some background info for you.
"M190: Wait for bed temperature to reach target temp
Example: M190 S60
This will wait until the bed temperature reaches 60 degrees, printing out the temperature of the hot end and the bed every second.
M140: Bed Temperature (Fast)
Example: M140 S55
Set the temperature of the build bed to 55oC and return control to the host immediately (i.e. before that temperature has been reached by the bed). There is an optional R field that sets the bed standby temperature: M140 S65 R40."
These two post my be useful for you as well for background info though I do not recommend changing any coding.