Either is good. I helped an explorer post build & fly four Sig LT-40s and they went together fast and simply. The instructions are pretty complete.

But, a warning: After some success with two-channel gliders I tried to teach myself to fly a glow Sig Kadet and I built it pretty but heavy. Ended up smashing it repeatedly without success and gave up for 15 years. An ARF and instructor could have given me a heck of a jump on my R/C skills. Don't build so much into your first model that its loss will overly disturb you. It's not inevitable, but it can happen. I know several pilots who still have their original trainers and use them as float planes and winter ski planes.