Does anyone know a source for the Megaview display for megasquirt?

one of these:
http://www.bgsoflex.com/mv/megaview.html

I though DIYautotune did them,but it appears not.

I don't think anyone currently produces one at the moment, however the link you've given has the schematics and BOM, a more detailed BOM is here.
The pcb should be reproduceable with some basic etching kit, have a look here for a starting point.
One of the ms distributors should be able to supply a programmed processor, as it is a ms1 processor with megaview software flashed on.

As an alternative, there are several homebrewed arduino display setups that offer more functionality, like this or this, have a look through the msextra forums for more.

Dave

Thanks I'll give those a look