Your plans seem sound. I have built up the black Nashbar cyclocross frame for commuting that is still working pretty well. Building cost more than buying used for me. I already had the wheels too but all the individual parts added up. I am in no way telling you not to build. Building a bike can be very rewarding and then you have exactly what you want. I am just saying exactly what you want will often cost more than "good enough" (buying something else used).