The rest is yours to OSRS gold decide. In the beginning, I’d suggest Torag’s plate and legs, offering the highest protection value ratio in the game (s’far as I know) Also, I’d recommend black dragonhide for the magic-based assignments you can begin working towards your Recipe for Disaster quest, that gives you the most powerful stat-boosting gloves in the game.
I’d also pick up an earring of wealth (can’t hurt) along with an amulet of glory , and dragon boots – which is the latter option if you have spare change. This is tiny strength bonus. All in all, the entire thing could cost 2.5-3m.
Combine the two and powerslay! That means you’ll need the best prayers for boosting your att/str as well as super pots for your assignments, and you can also use a cannon is also an option if to/can afford to. It can result in up to 100k exp/hour at the higher level, and that’s the same or even more than armoured zombies and bandits, and you avoid appearing as ridiculous as a person with 70 slayer.
Equipment should be: Barrows gloves, from RFD. Dragon boots. Full slayer helm, black mask until you get it. Use proselyte armor if you are using prayers. Barrows are a good alternative if you don’t. Whip, try to get an enraged rapier as quickly as you are able to. Dragon Defender, antidragon shield to tackle jobs involving dragons (DFS is too much, don’t spend the time on one).
Amulet of glory, try to get the fury whenever you can. Ardougne cape 3 or soulwars cape. Although it’s interesting but wouldn’t it defeat the aim of slaying? A big part of learning Slayer is something new to finish every job, and that’s sure is fine. But isn’t it also to make money? I’m certain that in the end, prayers would increase the cost to runescape gold 2007 where I’m losing money, doesn’t it?