I have, Altera, Vlad lll, Weaver, Chevaviler d'eon, Artoria Pendragon(Alter), Siegfried, Marie Attonette, Hercules, Saber Lily, Nursery Rhyme, and Martha
You could make a arts team with Waver, Vlad, and (support)Tamamo and have herc in the back just in case one dies and the other 2 slots are really up to you. (Might not be the best team you can make, i'm pretty inexperienced at this game)
Waver, Vlad, Tamamo is probably the best arts team you can make actually. I myself am using a team consisting of Jeanne, Vlad, and Tamamo (Support) and this team is already insanely strong. Now if you swap Jeanne for Waver, this team would even become more beastly. For the backline, I agree with bringing Herc as backup damager (tho you would prob not needing it as the frontline itself is already hard to kill). For the other backline, you could bring D'Eon or George as a taunter if you need it just in case if something bad happened and Hans for simply more support.
Considering cost limit, you might want to consider some lower rarity servants, such as Cu, Hans, Hassan of the Cursed Arm etc. It depends what you're wanting to accomplish, for Arts or just stacking buffs, use Hans, Cu for survivablity and Hassan for insane star generation. If you haven't invested in any lower servants, I would recommend you do.
