The 'ring is a small airplane and likely won't weigh over 30oz (especially if it's the S-1A version). The LA 25 has as much or more power than the venerable Fox 25 so start with .015" diameter stranded lines 60' in length. Current AMA competition regulations allow up to a .2550 cu. in engine while using .012" diameter lines but most folks find the .012's a little "stretchy".

I've flown my Fox 35 powered example on lines as short as 57'.