Hi Hawkfish

Welcome to ReefSafe
Firstly, the Tunze Doc Skimmer 9002 is indeed used by many RSM owners as it's much quieter than the stock skimmer (especially on the earlier 130 model, not so much with the newer 130D). This wasn't an issue on mine (I had a 130 before the 250), but if the tank was in your bedroom you might need a quieter skimmer. Both the Tunze and the stock RSM skimmers work very well.
There IS an issue with the Tunze not quite fitting though - the collection cup is just a bit too tall. As you say, you could cut a hole in the access flap for it (not sure how easy this actually is), or just run the tank without the access lid. If you want more info, I can PM you a link to a US forum which has lots of RSM modifications.
Secondly, it's nice to see another RSM owner here and it'd be great to see some pics of your tank - what have you got in there after 8 months?
Hope it's all running well
