Debo

Got a Spank Oozy 395+ wheelset. Well timed as I kept popping spokes on my old Duroc's.

I bought this for my son: https://www.rei.com/product/119073/co-op-cycles-drt-10-bike It's an XXS frame, hydraulic disc brakes, and front sus. On the higher end of your price range but no need to parts hunt.

The fork and frame may be able to accomidate a 29". I can check that later today. I bought it 27.5, never tried 29 on it.

UPDATE: The frame will not take a 29" wheel, it is 27.5" only 2017 Diamondback Release 2 frame size XL, comes with RockShox Monarch RT3 DebonAir rear shock, FSA headset, 135mm rear travel $400 2017 Rockshox Pike RC 27.5", 150mm travel, 35mm stanchions, comes with maxle 15x110. $250 SOLD 2017 Diamondback Blanchard 28 wheels, front 15x110, rear 148x12 rear with XD driver. Also comes with Vittoria Goma 2.4 tires set up tubeless. $175

I just put a Manitou Mattoc Pro 120mm on my new Banshee Phantom and i'm pretty pleased with it so far, especially for the price. I got it for $525 new from Chain Reaction. I was also slightly more limited on choices as I went 29+ on my build and Manitou seems to have embraced the 29+ market more than the other manufacturers.

40mm or less if possible.

I have a 29" rear wheel WTB i19 rim non boost. Also have the front but the rim is pretty bent, good hub though. Also a pair of Crank Brothers Mallet pedals with cleats. If anyone has a 31.8 clamp short stem I'm looking for one for my new build.

ATX Bikes carries Giant also.