Battlewagon and which Rolla?

I started putting the battle wagon together today, this will be for my Orks, the kit is fantastic, I've stuck in some Guardsmen for scale. The kit comes with a couple of options for weapon mounts and I was working on some way of magnetising them but it proved too much effort so I left it. I didnt glue everything so I can prime and paint the inside, I'm resolved that the Ork army will look a lot nicer to a unit than the Guard.

So here's a few pictures of the Wagon in progress.

Every Battlewagon should have a Deff Rolla, it's pretty much a no brainer upgrade for this Vehicle, it's only 20 points for a super advanced ram, this ram gives D6 S10 hits to it's target, troops and Vehicles.  With the front being AV 14 and that being resolved as well, this beast should kill a tank or anything that it comes across.

The big issue isn't a rules or points one it's a modelling one. When the Battlewagon kit first came out there wasnt any options to have a Deff Rolla, they had to be made from scratch.

Now I have two options, both at Extra cost, I don't really fancy doing any scratch building, I've enough to be getting on with. So here they are:

Puppets War Rolling Slaughter

Games Workshop Battlewagon Upgrade Pack

The Puppets War Roller looks incredible and costs €12 the GW Kit gives you a Kill Kannon (I think it's that) the Roller and a Grot with a spanner! for €10.50. the GW kit obviously just slots onto the current Wagon, I think in the end I will end up with more than 1 wagon. So I imagine that I'll end up with a couple of each. One thing the Puppets War Roller has is coolness, just look at the size of it!