I think your P30 will carry you a long way. No need to plan on replacing it already. The night sights will not be of value for most IDPA but they won't get in your way, either. I have one night sight with the whole front blade painted orange around the tritium lamp and it works just fine in any lighting conditions.
For a "tactical range holster" I recommend any of several brands of open top Kydex (synthetic) holsters with retention by friction and molding instead of a mechanical latch. The Blackhawk CQB rather than the SERPA.
Blade Tech, Comp Tac, Ready Tac, several others will be recommended but the type is well known.