I will be watching to see what you do up front. When I built the Phat Trakka, I used a pair of driving lights for low and high beams but to be honest, they could barely generate enough light see the front wheel and even then it looked like a film noir streetlamp seen.
So then I tried LED bulbs. Much whiter but still no depth of beam - hardly surprising. Then I went through a basket load of small LED lights and in the end had to fit a 5.75" LED headlamp without a shell but using a mounting ring.
That provided a great beam pattern and lights up the road effectively but looks like crap with the original front race type number plate. The current solution is a small "screen" above the headlamp but it looks a bit odd to my eyes - not like a tracker at all.
I did try a dual sport aftermarket number plate with small square light but it didn't look right either.
So I am hoping you come up with something that looks right that I can adapt for the fat gurl.
Big reason why I am going with an XL250r headlight. It's a rectangular, hi/lo beam street headlight. The XL250r shroud is unobtainium, and why I am playing with the XR650 shrouds. The XL600r and XR650 basically use the same shroud, while the 250r is different. I was originally planning to use DR stuff, but it's pretty pricey and lesser in design for this build, imo. I have DR350S ears, so I should be able to build a custom mount pretty easily to match the front end.
As far as front brake, I think the dual piston DR caliper will be plenty, but we'll have to see. Shouldn't be a huge gap in weight between this and a street-titled DR350 or DR650. There's an aftermarket 320mm rotor kit available through ProCycle. When this rotor goes out of spec, I will likely swap to that rotor.