Scottman, the heatmatt shown by Matt506 is a good matte to use. It will be more effective for you than not using one. At some point (maybe not this season) you may decide you need a heat matt regulator to more accurately control the temp around 85F. Depending on where you germinate the ambient room temp can be too cold or to warm at any given time. Or what is ideal one week might not be good a month later.
Hydrofarm also sells a regulator, Amazon.com, that will allow much greater control of the temp.
Good luck with your season
Mike