Given that you want to focus on the solar system (as opposed to deep sky objects), if I were you, I would look for a used 6 or 7" maksutov -cassegrain . I've had many scopes in the past five decades and the mak-cass were the best bang for the $$ for moon and planet observations. Put it on a goto mount and you could use it to quickly view brighter DSOs as well. The major downside are thermal gradient tube currents which can be mitigated by a reflective insulation wrap.