Use your mek skillz and cobble that bing together.
You got a Body, so get yourself some scraps and put them on the shoulders, then go get yourself one of those Titan cannons from over at Forgeworld and tap that on one side, or get yourself four and tap two on each sides More Dakka never goes bad! Make sure you get urself da shooty shhot bit~~
Seriously though,
You got an ork contraption there, what do you get with that? You can either pay double for a Titan that is by all intensive purposes a cobbled together, rattletrap machine of death, or you
can do what the rest of us do, and we get our bitz box, card stock, and odds and ends and make that thing your own.
GW has done themselves a disservice by making thier products cookie cutter. Used to be that we made the thing ours, and it was cool. Now, it's like conversion is a dirty four letter word.
You go on and make that, your other stuff is in the other box, next to the pet rock.
Make that thing and show some picks.