Simple Personal Investment / Wealth tracker for modelling what ifs.

Looking for a simple Excel based wealth tracker to run dynamic 'what ifs' across a 25-40 year period. Start point will be cash+assets (incl property) across different asset classes with different growth rates, assume base assumptions will be RoR and inflation. (I think all input categories will need several input sub options (ie rows?) for future additions . Need to take into account key future events at key dates inputs (ie property downsize, mortgage settlement, Capital influx, CGT tax outflow) as well as annual expenditures across a few ub categories. Like to see summary KPIs on Breakevens vs costs (dates), future net worth values at 5 year increments, IHT impacts etc etc Overall idea is to have a tool which is readily updateable as circumstances change. Keep it simple though!