yeah you can't get a trackish geo alu and carbon fork for 'not much money at all' but i think you have a pretty good idea of what you want and while everyone says the dropouts are weird on that 720tr, i say you should go for it.

if i were to buy a leader i'd just buy the 35r and forget about the 20 but whatever you think.

and wheel/tire choice/saddle choice are going to come into play a lot too. get a carbon seatpost.

and for the most part:
track geo is not comfy. they make track bikes rigid, not comfy. i think you'd almost be well served by a bowery or langster. by the time you build up that leader it will be more as expensive. and the only thing it will have going for it is the geo... maybe... if that. and canti brakes.

you're looking at 300 shipped for that frameset. plus 100 for a saddle and bars, a 100 for a headset and stem, 150 for wheels, and you're at a langster. cranks and chain is another 100 or more.

basically, by the time you have tires on the thing you're going to be kicking yourself for not just getting a langster.