Decent Gear For Level 40?

Simple Reply: Morph Set, even if partial.

Long Reply: Depends.

You can use various Lv. 35-50 items, and depending on what you want to build, you can consult the WynnData, which more or less acts as a cheat sheet for many items and the related builds. I recommend experimenting and choosing whatever fits your playstyle (filter by Combat Level 35-50, rarity Any except Normal, category Armour).

You will have limited access to stat points at that level, which means you need to be somewhat smarter about your stat allocation:

You can get the following gear from the quests:

• Avalanche: Fate of the Fallen quest reward. A very good Rare helmet at level.
• Mummy's Rag: Curse of the Mummy quest reward (name probably incorrect, let me know if it is). A Legendary chestplate with +1 Attack Speed - good for melee builds.
• Bob's Battle Chestplate: Bob's Lost Soul reward. It's a versatile chestplate that gives 20 stat points (4 in every stat), which is a boon for certain builds.
• Greggr's Hide: A melee Chestplate. It falls off pretty quickly and is overshadowed by Bob's Battle Chestplate and (if you're planning on doing Prison of Souls, which is a fairly difficult Altar at level) Marius' Prison.

A bunch of "use if found" items:

• Galloping Spurs: Fabled boots with good stats and (if you're using a horse) a decent utility boon, allowing you to use spells on horseback albeit with severe penalty. You shouldn't look for one specifically on the Trade Market as it will set you back plenty of money - I recommend saving up money. Their drop rate is also fairly low, at 1/10000[citation needed].
• Kaas' Fur: As Saya mentioned, it is a very good pair of Mana Regen leggings, and you can't go wrong with more Mana Regen.
• Ice Climbing Boots: A fairly good pair of Earth/Water boots.
  
• Giant Step: Gives stats, which will make your builds somewhat more versatile. Also has decent IDs.
• The Levee: 800 HP, in exchange for reduced spell/melee damage but increased fire/water damage, is pretty good. However do keep in mind that its stat costs might be somewhat restrictive in build-making.
• Cerid's Ingenuity: A superb pair of Fire/Water boots. Do keep in mind that they do not drop yet - they are a part of the next IM change that makes certain unobtainable items like this one drop from Dungeons (Emerald/Item rain, after completion).

Dungeon items that you can get by defeating (at level) Dungeons (there's only one since I don't have much in the way of weapon/armor choices):

• Blasphemy: 6/4s Mana Steal chestplate. Amazing for running both melee and spell damage builds, but requires a lot of Ice Barrows runs.

And a bunch of Boss Altar items - keep in mind that you need to get some friends to help you out if you're going to attempt Boss Altars:

• Sundown Poncho: A Legendary chestplate with amazing Fire/Thunder damage bonuses. Unfortunately, the Altar that gives out this reward is one of the toughest Boss Altars in the game (Sunrise Canyon).
• Marius' Prison: A Legendary chestplate with excellent stats overall. Get friends, because it is a very tough altar.
• Binding Brace: A Legendary bracelet - only Bracelet in this list. It is superb even in lategame, though you shouldn't worry about lategame.

Ask class builders to create you a working build. Most of the items listed here are Legendary, so I recommend not specifically going after them, and only going after them if you're planning to do more classes in the future.

EDIT:

Again, you need to complete Sunrise Canyon, but it is easily one of the best mid-game bows in the game, (possibly) carrying you all the way to Lv. 65! (Hawkeye is getting nerfed, but it will be still very powerful regardless)