Goat meat must be cooked very carefully since it is extremely lean.  The steaks should be "warmed up" low and slow (which means low heat and longer time) to no more than medium rare (internal temperature of 150ºF).  Some goat meat can be a little tough but some can be very tender.  This varies from critter to critter.  So we prefer to serve them rare (internal temperature of 140ºF degrees) rather than cooked to a higher temperature.  For sure they should be limber when served.  You may use any heat source.  We use a grill, but we never let the temperature inside the grill exceed 200ºF.  Goat has a great flavor but the small cuts are easy to over cook.