Alternative to "a bunch"?
A few more colorful alternatives: a ton, a mass, an abundance, a considerable amount, a mess, a slew, a spate, a profusion, a plethora.
A voluminous quantity of words in English can mean "a lot".
- abundance
- bundles/bundle
- collection (maybe "quite a collection")
- cornucopia (perhaps a stretch)
- clump (sure, why not?)
- conglomeration
- glut
- gobs/gob
- great deal
- heaps/heap
- hills/hill
- hoard
- load
- many/much
- masses/mass
- mountains/mountain
- multitudes/multitude
- oodles/ (or less common) oodle
- panoply
- peck
- piles/pile
- plenitude
- plenty
- plethora
- profusion
- reams/ream
- scads/ (or less common) scad
- slew
- spate
- stacks/stack
- superfluity
- surfeit
- surplus
- tons/ton
- whole lotta (slang, when spoken a certain way will mean more than just "a whole lot of")
Plus probably many more! Note that most of these take an indefinite article as in "an abundance", but no article is used for plurals. When there is a plural and a singular, the plural is generally more common, though not always.
Many of these can also be intensified with a synonym of large, plus this allows for additional words that are synonyms of amount. Some exampless:
- enormous amount
- gigantic quantity
- gargantuan pile
- _ of Herculean proportions
- truly Brobdingnagian _
- large multitude
- one major load -- "one" can be an intensifier indefinite article replacing "a"
Not all of the words in the first list work well with the "large" prefix--I wouldn't say "a huge plethora" or "a giant ton".
In general, when used with large, a plural word becomes more literal and seems to refer to many separate groups of items instead of one group. That is, "heaps of dirt" doesn't necessarily mean individual masses as it can be used figuratively to simply mean "a lot", however "giant heaps of dirt" more strongly suggests individual, separate masses.
Oh, one more thing, profanity can always be used to intensify. an [expletive] [intensifier] [lot] of [substance], or an [expletive]load for examples.
Regarding your more specific question, how about:
Now THAT is one sublimely prodigious pile of dihydrogen monoxide!
Many objects have their own collective noun, so you should start by trying to find and use that. Some are well known e.g. A murder of crows, a flock of sheep, a pride of lions, and some are obscure e.g. A dole of doves.
For objects where you don't know what their specific collective noun is, there are nouns which are well understood in broader uses, I've mentioned some below and their common areas of usage.
For all: Group, Collection, Multitude
For animals: Shoal (fish), Flock (birds), Swarm/Nest (insects)
For plants: Clump, Cluster
For non-discrete entities (water, earth etc): Body, Mass
Heap
You can use heap for anything, even if it's something that can't be heaped and even intangible stuff. You can pluralise it too into heaps.
Heap of trouble, heap of clothes, heap of love, heaps of water, heap o'shite, heaps of food.
Stack also works well
Stack of wood, stacks of dogs, stack of boxes, and all the above.
There must be heaps of words like this in English, probably even stacks of them.