dump valves dont exist in audi land (ok ok, but im not getting into it here !) Diverter valves do. Some 710s should do the trick.
Mapping is the way to go, but not REVO. If you want the best get a custom map from AmD/MRC......I went from REVO to AmD (revo in the 1st place as they were cheaper) and boy the difference was amazing.
Do the map along with the exhaust for "best" results.
Stay away from cone filters, they will kill your MAF and IMO suck in more hot air than cold. Panel filter will suffice