This comp looks to 3* the core units by slow rolling at lv5-6.
Kass and Garen will tank and depending on offensive items and augments both Kogmaw, Kass, and Graves can carry.
Be sure to not level in the early game unless you can ensure an early win streak (early 4-5 is ok, do not go to 6). Instead look to hit 50 gold as early as possible and then try to 3* Garen, Kass, and Graves at lv4-5. After that level to 6 and hit Kog and Blitz 3. Once all are 3* (or if the lobby is strong and you need to level to avoid dying) level up to 7 and 8 to round out the comp as needed.
Kass is the main tank, try to guarantee Warmogs and Gargoyles
AS items on Kogmaw - Rageblade, Giant Slayer, HoJ, Static Shiv, LW, Runaans, ect. QSS is also nice if he is your main carry or find he's dying a lot.
AP items on Malz - JG, Shojin(or Blue with mana reduction Mutation), Dcap, Morello, Archangels, IE (with JG)
AD items on Graves - Giant Slayer, IE, GA, BT, ect
Garen can take the scraps, he can use offensive or defensive if everyone else is full items. BT is quite good on him.
Featherweight is prolly your best bet as most of the comp is 1-2cost, but any economy (not march of progress)/reroll/hp saving ones work well.
Random synergy splash is ok too (socialite heart for example is always useful, even without a single socialite), anything that improves early game board strength and gets us to midgame without losing too much HP is ok.