Space marines have so many sets with so many options. I think they're ok. Don't forget there is already a Deathwatch bits pack (metal though).
Soooo Burlok's a recent release, they do options then. I'm messing with you a bit. I think your issue is the price not really the option which are largely irrelevant for named characters. Also if the models a plastic converting them is pretty darn easy especially with all the spare parts on sprites these days.
The other weapon on the close combat Sprue was the worlds widest auto pistol and yes no space marine would have used it.