engine swap for my 2500

Ok so im a bit torn about my truck. Ive got a 1997 ram 2500 that is in the process of being set up as a pulling truck. at the moment it has a 8.0L V10 in it but i want to put a diesel back in the truck. i dont want to go with anything new and personally want to steer away from as much electrical bullcrap as possible. torn between putting a 12V or a 24V in it. which would be a better starter engine for pulling? obviously it will be rebuilt before it sees a sled, and will have to be a stock or somewhat close to stock puller for a while but which would be better to look into?

Cheap route 12 valve.

would the 12 valve require alot of mods to get more power right out of the gate? or would that be an easier achievement with the 24 valve?