[HAM] What is the best kind of power supply to power up a high power car stereo amplifier used in a hot rodded Leslie?

[Kon Zissis]

Hi everyone.
My friend wants to replace the stock amplifier with a high power
amplifier in his Leslie 925 and I am wondering if a high power  car
stereo amplifier  such as  one with 200 watt RMS output level may be
suitable for the Leslie 925.
 
If such a high power car  stereo amplifier is used , then considering
that many car stereo amplifiers can safely be used with a 2 ohms load ,
then a 4 ohms  bass speaker might possibly be OK if the car stereo
amplifier is used as a bridged mono amplifier, however  the stock 4 ohms
JBL M 41-4 speaker may need to be replaced with a higher power rated
bass speaker. 
 
The stock JBL 2482 treble driver will remain in the Leslie 925 because
it has a very good fat sound.
 
Has anyone upgraded their Leslies with a high power car  amplifier and
if so, what kind of power supply  would be appropriate for this?
 
What kind of current rating would be required for the car amplifier
power supply ?
 
I think that when car amplifiers are used with a 12 volt  car battery ,
then ( if I remember correctly ) the  current draw is something like 18
amperes .
 
The local electronics shop sells transformer-less switch mode  power
supplies that are OK for testing high power car amplifiers , however
does anyone know if switch mode power supplies are OK to power up a car
amplifier in  a Leslie application or will the switch mode power supply
emit too much noise into the audio signals?
 
Thank you in advance for a reply.
All the best.
Kon