What do you think about the Athearn HO FP7 A/B MILW #94A/B

Hi there people.
I thinking of buying this loco [ATHG22226 = HO FP7 A/B MILW #94A/B]
http://railroadmodeling.kitmaker.net/modules.php?op=modload&name=Reviews&file=index&req=showcontent&id=7173
If I decide to convert it to dcc will I need two decoders? (One for each unit)
And if I go dcc can I set prototypical lightning effects such as mars light etc.
Any feedback on this model will also be appreciated.

Assuming both units are powered, then yes, you will need two (2) DCC Decoders. If only the A Unit is powered, then you only need one decoder (although you could then put a sound decoder into the B unit, which would have loads of room for the speaker, etc.)

Depending on the decoder, yes, you can set prototypical lighting effects. Note however, that this may require some additional surgery, depending on how the factory lighting is (e.g. if both headlights are connected to the same traces on the internal lighting board).