So far, I have picked out a lightweight crankshaft and an aluminum block. I need help finding lightweight, but strong, pistons to use, and which rod length. I'd like to maintain a safe compression for the addition of a supercharger sometime in the future. Also, can anyone recommend a pair of aluminum heads big enough to fit a 540?

Dart Chevy Aluminum Big Block
Material: Aluminum
Deck Height: 9.800 - 10.200 - 10.400
Cyl. Bore Diameter: 4.500
Caps: Steel or Ductile Iron
Cam Bore: Standard
Weight: 140 lb.
Part Number: Varies
Price: $6266.75
http://www.dartheads.com/products/en...ig-blocks.html (http://www.dartheads.com/products/engine-blocks/chevy-blocks/chevy-big-blocks/chevy-aluminum-big-blocks.html)

Callies Magnum XL Crankshaft - BBC
Stroke: 4.250
Main Bearing: 409 and Conventional BBC Main Bearing Diameters
Rod Journals: 2.200 - 2.100 - 2.000 Rod Journal Diameters
Weight: 58 lb.
Part Number: Varies
Price: ???
http://www.callies.com/crankshafts/magnumxl1.htm

I've been looking at some pistons and cylinder heads. Will everything work well together? How long should the piston rod be? I have a choice in deck height of 9.800, 10.200, or 10.400. Also, I think this engine will provide enough power without a supercharger, I doubt I'll add one now.

Mahle PowerPak Piston Kit
BB-Chevy PowerPak Piston Kit
Forged 2618 High Strength Aluminum Alloy
Bore: 4.500"
Pin Diameter: .990"
+13cc Dome Volume
Precision Ring Grooves: Included 1/16", 1/16", 3/16" Rings
http://www.jegs.com/p/Mahle/756703/10002/-1#bbchevy

Dart BBC PRO1 Aluminum Heads
Item: BBC PRO1 325 Assembled
Material: Aluminum
Intake Port: 325cc
Chamber Volume: 121cc
Intake/Exhaust Valves: 2.25/1.88 or 2.30/1.88
Springs: 1.550 Single or 1.550 Double or 1.625 Double
http://www.dartheads.com/products/cy...ro1-heads.html (http://www.dartheads.com/products/cylinder-heads/chevy-heads/big-block-chevy-heads/bbc-pro1-heads.html)

Have you thought of using JE Pistons? They have a lot of canned pistons but can also custom make anything you want.