Ideas for a single class party?

Clerics.

Call your group the A-Men.

I think the game is forgiving enough that you don't have to limit yourself in your choice. There are enough healing potions that you don't necessarily need a dedicated healer.

So just do what your heart tells you.

4 Barbarians. Just pick enemies up and throw them around like a pin ball machine.

This may not be the most optimal but I think a party of rangers, each with their own color dye would be fun. This way you could be the “power rangers”

I'd go druids. With spor Druid, you get tons of temp hit points and can tank a bit. Shape shifting allows you all kinds of utility in and outside combat. And when you die in animal form, you just go back to where you were before you shifted. Hand full of healing spells. Lots of summoning spells. My one druid gets like 7 summons before most fights start and a few during the fight.

Definitely druid. Shape shift everyone into ravens and just fly past every obstacle and enemy while playing Wagner's ride of the Valkyries.

Paladins:

• tanky
• solid damage
• lay on hands to heal (plus ancient's aura)
• can buff allies, debuff enemies, and remove debuffs
• charisma stat can be pumped due to being a charisma caster
• weapons w/ rush attack + high STR jump can cover lots of ground
• can feature a dex paladin running a bow
• if you went with 4 paladins all with a weapon with cleave you can do 12 smites in one turn by level 3.

Downsides of ranged and AoE can be mitigated with bombs or special arrows.1.

A Monk seems capable of soloing the game. Especially with clever use of throwables and improvised weaponry, positioning and shoves. They get 2 attacks right off the bat, don't need equipment at all, and are strong as fuck.

Of course, you can also just multiclass into every single class at once (even an achievement for doing this without using Withers) and practically do everything, too.

You have alot of the same answers but here is a wildcard. Sorccerer. Spells can complimemt each other very well, for example create water+ice or shock magic.

The biggest problem is, that getting the same equiqement x 4 is pretty hard. But doable in lategame.

The obvious answer is bard

Boring answer possibly, but Fighter. Can have each different one lean into defensive, dual-wield, ranged, two handed weapons however you want. Can have one or two be an eldritch knight for magic too.