from mcmaster-carr ($40)
1)  1/2"x12" hardened stainless steel threaded rod with nuts for main propeller shaft.   This allows me to clamp the prop, pulley and bearings to the shaft.
2)  10mmx6" nitronic stainless rod for intermediate shaft
3)  thrust bearing to support pushing loads on shaft from propeller without wearing out the regular bearings

from ebay:
1) 2x  fully ceramic ball bearings with 10mm inner diameter.  These are very low friction, do not corrode or need lubrication.  ($20)
2) 270kv  6350  brushless outrunnder for electric skateboards ($45)
3) motorcycle bearings for main shaft (eventually to be replaced by ceramic) ($10)
4) hdt5m toothed belts   9mm x 1meter  and 15mm x 2 meter  ($20)
5) 30 amp brushless controller ($25)
6) 20 and 24 tooth hdt5m aluminum pulleys ($10)

from hobbyking:
32x10 carbon fiber propeller ($60)   this is the largest propeller I could find for a reasonable price.

from hardware store:
screws and stainless bolts  $5

total: $235