Is there anything I can do if I want to check two answer as being good? What's the proper etiquette in this situation? I was thinking to just mark both answer up without a check and let the community decide.
Accepting isn't 'marking as best answer', it's 'marking as most helpful to the OP'. If one answer is not notable more helpful than another, and they helped you equally, remember you aren't required to accept one.
In any case, it is always a good idea to wait (I often wait 24-48 hrs) before accepting, because most users will be less likely to add another answer to a thread where one as already been accepted, and you will be more likely to get more feedback before ou click accept.
And of course, vote up any answer that has helped you.