I have a very old one and a relatively current frame, and one on order. Kalavinka's are easy to order, good frames, and can be customized quite extensively to your preferences. They ride extremely well, but bear in mind that their tradition is one of fast riding at or near the pole line on relatively flat tracks, so steering and handling are oriented in that direction. Bottom brackets tend to be quite high, fork trail tends to be quite low, and seat angle tends to be quite high with a very tight rear end. You can custom-order something different, but this is basically where they start.
The metalworking is first rate -- the equivalent of frames at twice the price. Finish is good but not at the level of a Tom Kellogg or Joe Bell -- however, the Kalavinka is a working bike for a racing cyclist and the paint is durable and well done. The Kalavinka doesn't have the sleeve-type stay-ends and fork tips that Nagasawas and SanRenshos have -- it's too bad because that's one detail that is very classy. But Kalavinka will offer you an internal top tube cable guide, curved seat stays, an amazing range of decals and paint finishes, and all kinds of other structural and aesthetic options.
If you want a lot of help with your fit, I'd deal with Tom Kellogg. You'll never go wrong there, and he knows track framebuilding like no other. You can also get an incredible level of detail finishing and paintwork. But in a Kalavinka you get frame, fork, headset, and bottom bracket all for $1200-1500, and you get a bike competitive with anything you'd put on the track. And Akio Tanabe is a great communicator with a great sense of style and personality. There are perhaps three or four really good keirin frame builders around today (and another 12-15 close behind), and while Nagasawa has the highest cachet, I'd say that a current Kalavinka is so close as to not be worth quibbling over.