For soldering them, you should use specially designed strips, but I am not sure where to get these. My friends from college's dad solders large solar panels with a torch :twisted: hehe
As far as encasing the unit with epoxy, it should be okay as long as there is careful consideration to the spectral light transmission percentage at particular wavelengths. I am not sure which spectrums a solar panel uses other then our visual range, you should research that, you might lose some efficiency if your epoxy acts like a bandpass filter.
As for forming some lenses.. You should pre-form these lenses and pour the optical epoxy into this. Do not try to sand or machine a lense into this epoxy block. The lenses have to be extremely smooth for them to work well. Sometimes if they are too rough, they will reflect light all over and stop transmitting completely.
Steve