I've got flat 89's and 70 pray. I am training slayer it's at 74 and I intend to keep training it. I already have Guthans and a whip but I need suggestions on armor and stuff if I want to keep training slayer.
Torags/Dharok provides the best defence bonus.
I personally enjoy using the Sara-sword as a weapon but since it's 2 handed, I suggest a whip.
Your best bet would to train with slayer helm, torso, dragon platelegs, dragon boots, etc...Something simple should get the job done.
20m doesn't get very far anymore :/
Do not buy an SS, an SS is really only good for pures for its special and such. But because you need more def bonus I would stick with the whip and have something in your shield slot such as a rune defender, rune kite, or obby shield.
SS and Whip are almost identical because of the fact that they hit at the same speed and have the same bonuses basically. The only thing SS is good for is for training strength.
I would try flipping if I were you, if you find the right items and do it correctly you can triple that 20m in a week or two.