Fire arms and Zombie Grave Yard

When ever a firearm is fired in "No More Room In Hell" a d10 is added to the "Dice Grave" which is then rolled at the start of the next turn for zombie reinforcements. (p.35 of the rule book)

 This means that once the shooting starts it is more likely that you will be surrounded by a zombie hoard sooner than later.

 Bows and Ninja stars have the "quite" rule, which means when used they don't add to the "Dice Grave".

 Browsing over the Hasslefree Miniatures site, I noticed a lot of figures with suppressed weapons, which had flicking through the rule book to see if there was a rule on suppressors on firearms. There isn't, at least, not that I could find.

So, I figure any weapon fitted with a suppressors are counted as "Quite" according the rule on P.11 and P.35.

 To prevent every character from having suppressed weapons, I would also impose the rule that a) only figures with weapons that have suppressors on them gain this rule, and b) a suppressor counts as special equipment and costs 20 POINTS.