Hmm, if you like to take the summon nature's ally route I could suggest:
Feats:
Augment Summoning
Imbued Summoning (+1 lvl, cast a free buf spell on your summon)
Rapid Spell (+1 lvl, makes it a standard action to summon)
Ashbound (summons are automatically extended and get a small bonus)
Items:
Nature's Children (Gives you +1 CL for summoning.)
Ring of Mighty Summons (3/day, max hit points, but half duration)
Ring of the Beast (Your Summon Nature's Ally spells are treated as one level higher)
Summoner's Totem (cast a free buff spell on you summon)
Feats:
Augment Summoning
Imbued Summoning (+1 lvl, cast a free buf spell on your summon)
Rapid Spell (+1 lvl, makes it a standard action to summon)
Ashbound (summons are automatically extended and get a small bonus)
Items:
Nature's Children (Gives you +1 CL for summoning.)
Ring of Mighty Summons (3/day, max hit points, but half duration)
Ring of the Beast (Your Summon Nature's Ally spells are treated as one level higher)
Summoner's Totem (cast a free buff spell on you summon)