This is like the whole Hulking Hurler idea, but with Dex.
iirc - the Shrapnyl something in MM2 has a dex around 35+
Then larder on the spells and feats and items and templates; not in that order.
Zegulak (spelling?) does the Shambling Mound con thing, on dex.
Epic gives room to bigger items, bigger CLs and MLs for various shenanigans.
These two approaches "ought" to give the biggest numbers, and maybe work together.