Allah has given clear instruction to marry the singles:
And marry the unmarried among you and the righteous among your male slaves and female slaves. If they should be poor, Allah will enrich them from His bounty, and Allah is all-Encompassing and Knowing.24:31
The one used in support of polygamy doesn't seem to be about polygamy when we start reading the chapter from the beginning. It says "mankind" and then Allah begins to give instruction on what to do with orphans. It makes no sense for him to have it for one man since its a matter of wealth. To be Muslim means to submit to peace or be peace maker. Allah is clear that another marriage does not leave a wife in peace. He also says there is no way two women can be treated equally which is very true. Under such circumstances, it is impossible to actually say he would allow multiple wives. He made a change in Prophet's case, but has also said it is restricted only to him.