two sources are Kitamura Kiden and vt4c. The KKK [ ] transformers I've found NOS or pulls from Ebay or surplussupply.com. I've also contacted Custom Magnetics, Inc. but haven't really acted on anything yet. I really like the vt4c, but expect a 2-3 month wait on a custom job though. Their specs are also a bit liberal... I'd figure 80% current draw that they state and then subtract another 15% for safety margin.
I'm talking on the order of 100VA or so, for oversized.
For EI I've used various Hammond transformers...
Here's the thread:
diyAudio Forums - Finally, an affordable CD Transport: the Shigaclone story
I'll be upfront and say I'm somewhat a Peter Daniel fan-boy :)