SGS is only good for the spec because it recovers hp and prayer.
Setup, I like to wear Bandos tassy and chest plate, whip + rune defender, dragon boots, slayer helmet, warrior ring, barrows gloves, fire cape.
If your praying a task wear a skill cape and Prossy. If you need more defence on a task replace your rune defender with a DFS.
Use a cannon to get to 85 the fastest, you still profit in the long run when using a cannon so really no harm in it.
If you can't afford Bandos wear Fighter torso, and rune or rock-shell legs.
and fast combat xp with 70M, seeing as you can't really buy combat xp... save your money and do Slayer, honestly you wanna be maxed by the end of 99 slayer not after.