Well nothing that some good media queries can't do to help you with the mobile resolutions if you will use only 'px'. It's good to talk with someone that actually cares about the entire process and have the complete picture of his work. I did suggest 'em' because 'px' can be really tricky (the absolute units make your head hurt so bad sometimes) but as long as you know what you are doing (and it's clear to me now that's your case) there is no problem with choosing the hard path at the end you are completely right it will bring more flexibility to your site. It's like the frameworks... they help for certain cases but not on all cases, there are many cases actually that is better to do a "manual" development than using a framework... some (most tbh) clients don't want to hear this things lol. Your work is amazing and I hope to get more news about your project soon! Regards bro!