You will need 6.5 quarts of oil, a 10 mm socket & ratchet to access the oil filter, an oil filter (i would only get one from Lexus because most of the cars I see that come from Jiffy Lube, or 5 Minute Oil Change have leaking filters), a drain plug gasket, 14 mm wrench for drain plug and a PROPER canister oil filter removal socket. If you are going to be doing your own oil changes on this vehicle, I would get the correct oil filter socket so that you do not round the edges of the canister filter cap. Remember, only tighten the canister filter hand tight and make sure you replace & lubricate that o-ring.
Oh, and the I've never seen a GS350 that had a drain hole on the oil filter. The ES, LS, LX and RX do have that however. There's no need for a drain hole since the filter is perfectly horizontal and will drain straight down when the filter is loosened.