A shield slot could require an illuminated god's book. Zamorak's book costs the ungodly amount of 22M an alternative is the book of law by armadyl costing 1.7M which is only
RS gold 2 less ranged offensives, however, it has defense capabilities and once you've lit it, you'll earn a big prayer bonus.
Your cape is best if it's not doing something that will not perform, such as shooting ogres in cages. In that case you should wear your best ardougne cloak
buy OSRS gold or something with offensive/prayer bonuses. Dragonhide red, of course, unless you're looking to go void. I hope that can help!