which dc controller

I think Baskin has a controller that controls two seperate fans. How many connectors come on your new E-fan?

I have a 1996 Mark Viii and a FK35. It works better than I could have hoped for. If you can not find it on the site, just send an email over to support@dcc.com. Baskin is one of the best at customer service.

Just an alternative to a DC, a little bit less expensive

I've been using a Flex A Lite Variable Speed Controller
which also soft starts the fan motor(s) to avoid the big
spike in amp draw on startup.

Been working like a charm.

About $100 - you'd probly need the bigger of the 2
as listed on Summit

http://www.flex-a-lite.com/auto/html/vsc.html

Oh, and no relays needed.