I understand what you're trying to do but it's one of those things that really isn't going to be worth it.
The benefit of a longer rod/stroke ratio can be easily offest with making more horsepower. To use V10 rods is going to probably cost you the same amount as a nice low cost performance rod once you resize them and fit new rod bolts.
edit: Sorry got cut off by my wife wanting the computer
Anyway, any engine where the benefit of the longer rod will make a difference will have a horsepower rating that exceeds the rod's capacity, or if used on a lower horsepower engine, the same horsepower benefit can be found elsewhere for lower cost.