From what I can tell about Utah's requirements - and I could be wrong, for sure - there's no emissions testing required for motorcycles, and the following somewhat-weird schedule for vehicle safety inspections:
http://dmv.utah.gov/vehicles-services-m ... nspectionsIt seems to me that a 1975 vehicle registered now would require an inspection, but in 2014 might not - but who knows. I'd highly recommend applying for the title and having the VIN number checked by DMV, then trying to register it - that's all I did, it worked fine for two bikes in CT.
If DMV requires an inspection and you're going to have to put on all that stuff, I'd suggest an MT125 wiring harness, which should have connections for all of it and then some. If it were me I'd hook it up using a battery; the MR175 lighting coil doesn't have a whole lot of reserve capability, but it should be able to charge the battery OK. If you're planning on doing a lot of night riding, you'll probably have to send the stator out to be modified.
My bike had a brake switch (probably an OEM Honda part) mounted in the extra hole in the front brake lever mount designed for it, which is easier than rigging something up to the rear brake pedal.
Ray