Yes, i'm using dpkg to install the packages i downloaded from debian.org. I not sure if i understand your syntax. What does '<pathto>' stand for? Anyways, here is what i typed into shell:

dpkg -i libxext-dev_1.0.1-2_i386.deb libx11-dev_1.0.3-7_i386.deb


Does that look correct? Yet, i get the same error as before, stating that libxext-dev & Libx11-dev depend on each other, and it refuses to install. I guess i could try apt-get, but, like you said, that might end up doing some 'drastic' changes that could render my system unusable, which is why i avoid it whenever i can. Maybe it's time to get Debian, but i need it tailored for music production. Besides 64 Studio & Ubuntu Studio, what other 'Debian-based' options do i have?