Take a look at Wedding cake pillars. Most are
cylinders, but I have managed to (on occassion)
find some that are squarish, & therefore usable
for Egyptian temples.
For statues look at 1/72nd plastic for chariots &
54mm plastic for heroic warriors.
A box of relatively cheap 1/72nd plastic can also
provide some relief detail on the walls of temples.
There is also a favourite of mine, car-boot sales &
charity sales. From the former I got a bag of pens
with Egyptian gods on. They were dirt cheap as,
'The pens don't work'

.
From the later I picked up an Egyptian chess set,
again dirt cheap as, 'There are two pieces missing'

Good luck on your project.