All the above messages have offered advice on radio, motors and aircraft etc., but none have touched on the problem of building the LT40 straight and accurate. For a first time builder it is easy to make a mistake, grain wrong direction, wrong glue and many other little places where a novice builder would be unaware of. The Sig LT40 is a fantastic trainer and also a good second model to "throw" around when you have mastered the controls. However a poorly built model can be a handfull for an inexperienced flyer. An experienced modeller could cope and sort out the problems.
When Sig originally kitted the LT40 it was a similar to others,die cut parts etc. However when they brought out the ARF version, I noted the kit now came with laser cut parts as used in the ARF. Agreed this would make it easier to assembly it accurately but with the kit you get no wheels,tank spinner, covering materials and from memory the kit was more expensive than the ARF version. The quality of the ARF WAS excellent but I have read that Sig's ARF quality is falling.
My reccomendation is put the kit aside until next winter, if available purchase a ARF Sig LT40 and use that as your basic trainer knowing that any flying mistakes are more likely to come from any source except from the accuracy of the model.
I enjoy scratch building models but it is difficult to build as light and accurate as today's quality ARF and a lot more expensive. I would estimate the cost to scratch build a model is 3 to 4 times the cost of an ARF.