I have 3 sets of Carrillo 6.200 rods here

2 are honda journals

1 is IRL

Not sure how exotic you want to get but you could get a crank made with Honda journals and you could run lightweight rods that cost you around $3-400, if you get lucky you could get them even cheaper. I think the cost either way would be a wash. Going with the Honda or IRL journals will save alot of weight plus you are already talking very minimal CH. I don't think it'd be unreasonable to say you could have a 4.125 stroke and only have 1400-1450 BW.