Easiest way to do 10 gallon batches...

Well, I think I want to do full boil 10 gallon batches and eventually go all grain. Here is what i'm thinking so far:

Build a complex, expensive "Keg" 3-tier system
Build two cooler style systems with 2 turkey fryers and boil 2-5 gallon batches at once.

It seems the cost of equipment goes up very significantly when you prepare to do 10 gallon's at a time. Looking for some cheap alternatives!

I do batch-and-a-half's. That much wort almost fits in my kettle, if I add some after it boils down a ways. 15 pounds of mash fills my five gallon bottling bucket (that I use to sparge) right to the top. Ferment in two 5gal carboys. No additional equipment needed, little extra time over 5'ers. No hernia from trying to handle 10 gals at once.

I guess a big keggle would allow 10 gallon batchs?

Any ideas on taking advantage of the two small ferments? Besides cold hopping? Fruit? Other late modifications?