I went with two bottles of spray and roll-on from Amazon

[Shameless Amazon affiliate product linking to support my Biofreeze habit]

The spray version seems to have the highest concentration, although the roll-on works the best for no mess application, and the plain gel for best coverage.  I would recommend against getting the large bottles of the gel because it loses its effectiveness too quickly and the pump doesn't do a good job of dispensing.  Use the smaller squeeze bottles if you go for the original gel form.