looking at getting an xl station wagon but it has drum brakes alround wat be the setup to change cheaply

another brand car would be the solution.

You may need different upper arms, and lower arms, then use XF/XG stub axles & brakes. Use the master cyl & booster too.

maybe give someone like hoppers stoppers a call, they sell kits for this kind of thing.

Theres nothing wrong with 4 wheel drums just run a vh40 or 44 with then and they will stop fine as long as you dont want to win Bathurst.
The cheapy option is to get the stub axle callipers and rotor of an XY - XF falcon and transplant that using a shim on your tie rod as XW back is a smaller size if you do this you will nedd to run an XB master cylinder and vh40 or 44.
The other option is brum brake stub axles with an adaptor to fit XY - XF rotors and holden callipers remembering to use XB master cylinder and vh44 or 40.
Remember that doing this will change your front stud pattern so your diff will have to be changed.
Also changing your camber caster rod bushes will aid brakeing.
Hope this is a help.