Welcome to the forum Bluesman.
If you plan on using dropped D tuning, then I suggest you get a copy of Kirks book "Plane Talk".
As a professional guitar teacher, I have seen and used a lot of different methods on approaching harmony and theory, and I consider Kirks book to be among the best.
As for your strat; get a set of either .012 > .052 (or) .013 > .056 nickel wounds, block off the whammy bar with either a small block of wood or some folded up paper (at the back, behind the tremelo block) and tighten the spring screws as far as you can to get the bridge sitting flat.
Raise your action a little, and maybe tighten your truss rod a little too.
You may have to widen the slots in the nut also. (Just use a bit of wet and dry sandpaper folded over).
I've posted measurements here and methods as well, you'll just have to find them.
I prefer a bottleneck for a
slide, but anything will do, so long as it has a little weight behind it.
As for blues slide, I like pre-war blues a lot; guys like Tampa Red, Blind Willie Johnson, Son House, Charlie Patton, to name a few.
Chicago blues is also great, check out some early Muddy Waters, Robert Nighthawk, Earl Hooker, Elmore James.
There is more to this music than you may at first realise.
Good luck.