Very low budget 360

I'm looking to get 300-350hp as cheaply as possible. How close do you think I would get with the following?

stock short block

308 heads - stock apart from port matching, minor clean up and milling to increase compression to about 9.5:1

cam - open to suggestions, i like the idea of running a solid cam and have 273 adjustable rockers (are they worth using even if i run hydraulic?) it's going in a 4 speed car with no power accessories so i don't mind a lumpy idle but don't want to kill mileage - would like at least 15mpg

Weiand dual plane manifold

Carter Thermoquad or Holley 750 v/s

headers - any preference between tri-ys and 4-1?

2.5" dual exhaust

Any comments would be appreciated