Bodies will sell a lot easier than shields, only people buying them will be merchers as they know they can buy them cheap and sell for like 5% more gradually.
15,109 Bodies = 45,327 Hides
11,332 Shields = 45,328 Hides
Dragon leather = 4,830gp
Cost for Bodies = 218,929,410
Cost for Shields = 218,934,240
Sell Bodies Med = 7,712 ea = 116,520,608
Sell Shields Med = 9,614 ea = 108,945,848
High Alch Bodies = 8,088 ea = 122,201,592
High Alch Shields = 10,783 ea = 122,192,956
Nature Rune 296 ea G.E Med
Cost of Nature Runes Bodies = 4,472,264
Cost of Nature Runes Shields = 3,354,272
Total Loss Selling Bodies Med = 102,408,802
Total Loss Selling Shields Med = 109,988,392
Total Loss High Alch Bodies = 101,200,082
Total Loss High Alch Shields = 100,095,556
The lowest loss is 100,095,556 by doing the Dragon Shields, buying all hides at med, and buying all the nature runes at med price.