Regulating 2 DC Desk Fans

Hey there,

I'm planning on building a setup for my Racing setup.

I'd like to place 2 desk fans on either side of the steering wheel and connect those to an Arduino Uno.
The Arduino is then connected to the PC which gets it's data from SimTools 2.0.
Then when you're racing in the game the speed of the fans is regulated based on how hard you drive, and if you're turning your wheel (going left makes the left fan blow a tad harder)

Now I've done some reading on what I need for this but to be sure I'd like to verify that my idea is valid.
At first I wanted to use AC fans, due to them being able to output more wind, but as far as I've read, AC is way harder to regulate. So I've chosen two 12VDC Desk fans wich use 50W each (4,16A).
Then to use with that I've selected a 8,5A (120W) Meanwell power supply to feed them.

Then as setup I'll use the setup described as first setup at:
http://www.thebox.myzen.co.uk/Workshop/Motors_1.html
Using two TIP120

I was looking at the Adafruit Motor Shield, but that doesn't seem to be able to feed the fans I had in mind. I have a feeling it's more based for servo motors.

So my question is, do any of you see something faulty with my setup here, or do you think I can proceed with building this ?

I would use a power supply at least 50% bigger than than your max power consumption, running near 100% will make it run very hot and probably fail early. If the fans always run the same direction, you don't need an H-Bridge type motor board, just 2 logic level power MOSFETs. Here's one I like (of many):

You certainly have a valid point with the PSU. I'll go for a: Mean Well SP-240-12

As for the MOSFETs, would this suffice ?

I've searched for the ones you mentioned, but I can't find those on my local market. I recon a IRL540N would suffice as well ? It's 100V, so would suffice more then enough.

I'm only not sure for the diode. Would a standard 1N4004 be sufficient ?

Datasheet for the DC fans?

MarkT:
Datasheet for the DC fans?

Sadly, there is none. It seems to be the standard with desk fans, as there's hardly any information to be found. I haven't found one which shares detailed information on the motor being used :
http://www.carpoint.nl/product/ventilator-3/