RE: Advice on Servos 1.2/1.4 size plane
will they fit the connectors?
yes
Some JR servos have very tight dead band and if used on Y's with one reverser and some other setups - they can get antsy but if the system is properly laid out - the $30.00 MAP price 821 -for example should perform properly . These have 72 inch ounces of torque at 4.8 v and are far better than servos we used in much larger aerobatic competition models in the 1990's
40 inch ounce was the standard then
For your size model - these should work even with fairly extreme throws.
I use 5 cell rx packs which boost power - 15%- roughly
Most setups where servo power and performance is bad - are simply not properly setup .
By using full servo rotation and well operating control linkages (not expensive - just smooth no binding ) servos with lower advertised power can do extremely well .