MB 126 380sel, new cams or engine swop ?

HI!
I just bought a MB380SEL 85´ in Munich this friday. Very nice and clean car but it has the weakness of damaged cams and valvehydroes (288.000km.). It has a 2-way catalysator and Niveaumat suspension as well
as a full leather Recaro classic seats in nice cream colour. ABS as well as Airbag and safetybelt tighteners.
I would like to know if it is recommendable to rebuild the engine top with new cams and valvegear. Or would it be better to change to a 420 or 500 engine. If the latter sugestion, then what about the electric equipment, wirering and stuff. Would I have to change a lot of part besides the engine.

I would appriciate any hints or answers on this topic.

Regards
Henrik Toft
Copenhagen
DENMARK, Europe

Here are my cars for the moment
MB 124 300E Lorinser racinggray 1985
MB 126 280 SE blue with SEC front 1982
MB 126 380 SEL grey MB color 702 1985

------------------
Henrik