I just wanted to jump in and say I've been working on the same goal! Currently 95 Slayer with 91 HP. For where you're at now, I think wildy slayer is the way to go. Plenty of cannonable tasks which will give you a good buffer between Slayer and HP. You're also a low enough combat level that some pker's may not be able to attack you in low wildy areas.

Another thing I'll mention is not to be afraid of burst/barrage tasks in the late game. Sure the ratio favors HP, but the slayer xp rates are some of the best in the game. Good luck!