Gramps?

Ok so first of all I've already decided against rolling for Merlin. I'm just gonna use one of the dozens that will no doubt show up in my support roster. Now then of all the banners coming up I'm really confilicted. I have whaled before but I'm trying to save money atm. So I'm only really willing to whale once, maybe twice for the next couple banners. After thinking about it I'm kinda leaning towards going for gramps. I was thinking about going for Musashi or Nero Bride but after some thinking I'm really leaning towards Gramps. What would anyone recommend with my list of currently leveled servants?

Saber:
Mordred - LV 100
Altera - LV 84
Archer:
Gilgamesh - LV 90
Lancer:
Karna - LV 90
Lancer Alter - LV 80
Rider:
Santa Alter - LV 80
Summer Mordred - LV 80
Caster:
Waver - LV 90
Tamamo - LV 90
Assassin:
Shiki - LV 80
Scathach - LV 80
Berserker:
Heracles - LV 80
Lancelot - LV 70
Ruler:
Jeanne - LV 90
Avenger:
Jalter - LV 100