Hi there, hope this helps:

I've got some references to tricks I posted, two very heavy
ideas which use some odd scales,

Bhairava scale
http://www.guitartricks.com/2000/trick.php?trick_id=3382
Hungarian major
http://www.guitartricks.com/2000/trick.php?trick_id=5038

These are very obscure scales and learning them won't teach you to play much anyone else has bothered to write! On the other hand you might like the heavy sounds of them playing metal as you do.
The most important metal soloing scale may be The harmonic Minor Scale.

Here's A harmonic Minor:

A B C D E F G# A

Chord are:
A minor (ACE), B (BDF) Diminished, C (CEG#) Augmented, D (DFA) minor, E (EG#B) Major, F (FAC) Major or F (FG#A)minor G# Diminished (G#BD)and Augmented (G#CE).

i HOPE THIS HELPS.

As for strings, well, finer gauges are better for bending but their tone is thinner and less rich. Personally I think fine gauge strings are fine if you've got the sound you want from your anp and fx and use 09s.