Cheers guys.
I was thinking about casting it up as I wanted to do a couple for use as objectives and the like. However I'd get it professionally done as it's a bit too detailed for me to reliably get all the detail in there as I don't have a vacuum chamber. I've tried Gothic stuff before and despite my best efforts they still have little bubbles in the corners of details - which is ok for gaming stuff or scenery but not to sell to other people.
I am going to go for a more rounded prow (it's only supposed to be armour 5) but I could make the prow separate and make more of an armoured one later? As for the weapons, all GW Imperial weapons fit in there but the Weapon Batteries sit a bit further back. I will make some fuel pods though.
Dreadnoughts are Pre shield technology. From original fluff I think they are literally gigantic battering rams. Battleship+ scale versions of brute ram ships
This chap is going to be a bit chunky and fat. Rather than the long and elegant Dreadnoughts but what you do with the model is up to you though