Gidday, like Pete says, why limit yourself with small radii curves especially if you are going to run larger locos?
While forum member mcfunkeymonkey models N gauge, his techniques translate to any gauge and his threads and how-tos are definitely well worth a look. Here’s some links…
http://www.youtube.com/watch?v=wM1H0URvKX8
http://cs.trains.com/mrr/f/11/t/212393.aspx
http://www.youtube.com/user/mcfujiwara925/videos
The only difference is instead of PC board ties at the module butt joins, I use brass screws.
Cheers, the Bear.