Dear Olivier,
If you are looking for an highly skilled hardware engineer, I believe that I am the one who you're looking for. I am also an experienced PCB designer who has over 16 years design experience on complex PCB design. I can provide you with design service from schematic entry(circuit design) to PCB layout. I can help you prototype the PCB.
EDA Tools--ALTIUM DESIGNER16, orcad, PADs, Eagle
I am interested in your project and I believe I can do it well. The reason are,
(1) I am familiar with Freescale IMX chipsets. For example, IMX28 (successfully built) and Several IMX6 related products. (I helped my client design custom design IMX6 board last month)
(2) I also have other Linux platform design experience. Normally I will work closely with the firmware engineer to get the project done. Extensively, I have experience on RF board design experience, this will be helpful to your 3g module integration.
(3) I have necessary resource here in my local to order PCB, purchase component and assemble them. Then I will test them. Even you select the engineer lives in Europe, they could have to order PCB from china.
(4) Electronic knowledge, I have many years design/debug experience. I think my knowledge base is enough for your board design something like vol monitor, solve current/voltage etc...:-)
The only issue is, I am based on china. But nowadays, work can be done remotely via internet...
I hope that you can message me if you are interested in my service. We can talk more.