The 120mm Evostar is at the cross-over point where for a refractor, there is enough aperture for good deep-sky performance, but light enough for mounting ona fairly insubstantial mount. The EQ3-2 can be upgraded to RA tracking or even full GOTO

120mm (4.75″) f/1000 REFRACTOR TELESCOPE 
Skywatcher supplied product information –  

Our view

The largest refractor we recommend for the EQ3-2 mount. Larger or heavier telescopes require the EQ5 or better. The 120mm Evostar is at the cross-over point where for a refractor, there is enough aperture for good deep-sky performance, but light enough for mounting ona fairly insubstantial mount. The EQ3-2 can be upgraded to RA tracking or even full GOTO. An excellent white light solar refractor by adding some Baader Astrosolar over the front aperture. An affordable instrument for schools to purchase for science project astronomical observing. 120mm is easily enough for visibility of all Messier objects as well as good lunar and planetary detail.

Tips

Budget for an A4 sheet of Baader Astrosolar and a weak sky pollution filter such as the Baader Neodymium 1.25 filter. Budget also for a 1.25″ Baader polarizing set or a 1.25″ Neutral density filter for the moon. It is also worth considering a 6mm eyepiece for the moon and planets.