A couple of thoughts...
First up, is this a new guitar to
you that always has this problem in your experience, or has it only just started occurring
on a guitar you've owned for a while?
Second, it's worth checking the the
mountings, not all microphony is due to the coils or covers, sometimes it can come from
the height adjustment screws and springs.
Third, The standard SD Alnico II and
JB are without covers but the BM 2.13i has covers fitted which SD can usually supply as an
aftermarket part. Might be worth an email to Brian Moore to find ask them how they specify
their pick-ups from SD, I know that SD pot some pick-up models but not all. BM should be
able to advise whether or not the pick-ups they use are potted or not and if they are
whether that is done before or after the pick-up covers are fitted.
while I can see that Blutack might work in the short term, it does go hard and dry out
over time and wouldn't want to trust it long term. I don't like the thought of dry,
brittle, pieces of old Blutack breaking off and getting into the coils and potentially
doing damage. Wax potting is proven and benevolent, it is safe for the coils and if the
wax in a potted cover does come loose an experienced pick-up maker/repairer can often fix
it with a little heat carefully applied.
As for changing pick-ups, I would
treat that as a separate issue. If the existing pick-ups do a good job when working
properly I would get them sorted. If you think a change would be worthwhile, try to get a
clear idea in your head what you find the existing pick-ups lack for you and then give
some of the pick-up companies a call and discuss the options. Metal covers generally work
just fine, so they aren't really a risk. But they do change the sound of a pick-up
slightly, that's one of the things the pick-up makers would consider when discussing
alternatives, and it might be worth having a look at the FAQ's on the Seymour Duncan site
(especially Seymour's own FAQ's, there are about 250 of them and they are unstructured but
make interesting reading for a couple of days). I've also heard good things about Iron
Gear, but haven't heard them myself yet. However, don't forget Bare Knuckle who could also
help with repairs/potting.
When the going gets weird, the Weird turn Pro.