The ecu may get rid of the limit, but I don't think the car would go much faster due to drag, it would certainly take awhile to get there.
Then there is the issue of tires, are the GA tires V-rated? A blowout would be bad at 100+
A suspension upgrade for stability.
A brake upgrade so you could stop from that speed, stock breaks would fade really quickly leaving you with none.
There are better mods for the cost, the ECU is not usually the first one people get.
For power, try a header, intake , pulleys or cams first. Then either an exhaust or ecu.
Don't forget suspension and brakes for better handling.
These mods make a driving at lower speeds enjoyable so you won't need to go to top end extremes.
