I received this reply today from Ctek:

Hi,

You need to review our PS400 or EPS1245 both are within this link.
http://www.element82.co.nz/Products/tabid/170/CategoryID/97/Default.aspx

The first is a power supply with charger functionality. The second is a charger that will increase voltage and current as required but is not a power supply as such like the feature offered with the CTEK XS7000 you may of seen.

Additionally the CTEK when in power supply mode doesn't have reverse polarity protection or anti spark as its supplying power from the time its turned on. I believe either of the EPS units would work with a small compromise for one feature from each that may give you your alternative your looking for.

Not sure what the prices are on the product (DBL800) you've noted but our units are around the $980+GST

Regards

So really I am still looking...