914-6 air conditioning, Advice on compressor choise Options

[turboman]

Hi, I am in the process to install an original 914 VPC system in my 914-6.
Like all my projects, I work on a budget.
First I bought all the parts about 5 years ago, then I refurbished all parts, (professional cleaning, expansion valve) installed the condenser in the front trunk as designed, temporary installed the evaporator console under the dash, and start the preparation process for the compressor installation.
I want the installation to be as close as possible to a factory one.
For me, is not an option a compressor under the engine, a serpentine belt or similar. I prefer to work extra time, and reach a perfect end product.
I used a double pulley from a 74 911, in order to install the pulley and have space for the dual belts, I have to shave a bit the original engine support and the engine cover (see photo).
I fit a 2.2 or 2.4 bracket. So far no problems, the end result looks very nice
Now I need to choose the compressor.
The York is out of question, due to size and efficiency. My options are a Sanden, a Denso or a Panasonic. Any one fitted with a one groove pulley
Not being familiar with the air conditioner compressors, and the way you need to calculate cooling capacity vs cabin volume, I would like to ask help form all of you.
1. Which compressor will suit my needs the best?
2. Which compressor is the smallest one?
3. The best compromise?
I will keep all of you posted of the progress on the installation and the need or not of a firewall modification.
Thanks
Francisco

[turboman]

As I mentioned I got in contact with Michael at Mittelmotor in Germany http://www.mittelmotor.de they made an instalation of a VPC Cool A/C into a 914-6.
No modification was made to the firewall.
Look at the photos.