It is a really good idea to put new springs in during this procedure.... on cars as old as ours typically are.... they have been through you know what and back.... and particularly on a car which has not had the engine turned over for a while... lots of cases of one of the latter breaking... due to having been compressed for an extended period due to lack of engine use.

In rereading Raymond's post...I am not sure why the valve seals are paired with the turbo work...
The seals should be less than $25 at most.... and the only gasket you might want would be a new valve cover rubber seal....