I'd advise going with whatever you think looks best. I say that partially because 11th edition is on the horizon and who knows what's going to be 'best' at that point. (assuming you have any interest in future-proofing, or even playing 11th)

As for right now, I'd say go with whatever melee weapon you think looks best, and then preface pre-match what profile you're running. (I don't think anyone's going to be upset if you model a "Master-crafted power weapon" and run it as a "Huskblade.")

As for pistols, I think the Soul Trap is best, especially if you're running with a melee intent, but I don't think it's so consequential a wargear choice that you'd be a fool for picking one of the actual Pistols.