any advice would be appreciated

[oddiseey]

i live in connecticut...im looking to get a gunite pool 16 by 32
it will be built on a slope on an area which has about 4-5 trees and some brush...since its a slope ill need a 7-8 foot retainer wall...this wall will be around 40 feet long...gonna go with some low end blocks...will also need a patio built with some bolduc type blocks...patio wiould be all around the pool...around 12 foot by 10 foot on the ling end ....4 feet around each side and 8 feet by 8 feet on other end....since we live in ct we want to get a heater and also a self cleaning pool...
the wife is pushing to add on some kind of spa ....questions occur here....how much more should a spa cost? what are the options"? does it need a seprate pump and if so how much is that..does it need a sperate heater and if so how much is that? how much should this entire project cost?