Since the rods are not a common item (2.100" weird journal size and 6.76" length) I don't think you'll find any used (and never buy used aluminum rods!).
Clearance problems as CNC-Dude noted, plus H beams (most Carrillo) are even bigger.
A long rod, which is what you want to get the piston weight down, interferes even more with the cam, but I don't know how much - it's just not going in the right direction.
Unless you want to weld the crank, there's really nothing else that fits - all the long rods are for journals bigger than 2.100".
If you need a rod made, consider searching for a quality "shelf" piston (SBC, etc. stocking item) to save some money, since the rod length and pin eye can be made to match this.
