It went from custom to Surly because the OP and respondents raised questions about what the OP really wanted, and what he could really expect from a custom Keirin builder.

Not having lived in Japan, myself, I don't know how much, in terms of the Japanese economy, a custom Keirin frame costs, but I assume it doesn't come cheap.

The Surly/Leader/Viking frame could put the OP into a learning and riding situation where he could determine HIS fit and components, and then have everything ready in his head when he finally went to a custom builder.

I have a custom frame.

It took me four years of study and thought to design it.

In the end, it has geometry remarkably similar to my 2005 Bianchi Pista, but it took me those years of study to understand how that specific geometry and certain specific components would work for ME.

I suspect that in the end, the OP will pick a standard geometry Keirin frame that gives him adequate stand over height, and he'll refine the fit with proper components.

He could do that now by just choosing a standard Keirin frame size based on the inseam of his trousers.

However, if that seems like too much of a risk, he could get a Surly/Leader/Viking frame and ride while he learns what he wants for himself.

In the meantime, www.businesscycles.com soemtimes has a number of standard/stock Keirin frames, some of them drilled for a brake:

http://www.businesscycles.com/ganwell.htm

http://www.businesscycles.com/nagasawa.htm

For myself, I'd buy a 59cm Ganwell Pro frame if I wanted a Keirin track frame; but, based on my experience riding this type of frame, I know I'd need a 35mm setback seatpost.

If I had purchased this frame five years ago, for the stand over height, I would have perceived the top tube as too short and I would have initially tried to get more cockpit space with a longer stem.

Unhappily, a longer stem would have put too much weight on the front wheel for riding on the street (different than riding on the track), and the resulting handling and body position would have convinced me I had bought the wrong sized frame and that I needed a custom geometry frame.

In reality, though, I don't need a custom geometry frame.

A stock geometry frame will work great for me, if I choose the correct components for my body type and riding style.

For me, if I want an agile street bike, I know to choose a frame one size smaller than most bike shops would recommend, and that a setback seat post will properly position me over the bike in relation to the front and rear wheels and the bottom bracket.

I have short legs, a long body, and I ride only on the street; and so the above works for ME.