I do plan to have a sump-- but I don't want to drill the tank, 'cause I can't find anyone locally who will do it. The LFS guy showed me some overflow systems that they use to connect the sump to DT, which doesn't require drilling. I had planned on putting that remora into the sump.... it's packaged as HOB or in-sump use. is that wrong?
you are correct. Drilling a tank is actually not difficult at all. I will guarantee there are MANY hobbyists in your area who would do it for you for free. And any decent LFS will drill it for something like 10 or 20 bucks per hole.
Overflow boxes are bulky, expensive, and prone to failure. (I don't want to hear the "had one for 20 years and it hasn't failed yet" responses, the bottom line is they will fail long before a simple hole will.) Overflow boxes IMO are designed as a way to sump a tank when it wasn't originally planned to be sumped.
Don't be afraid to have a DT drilled, it's not as scary as it seems. You just need to make sure it's not tempered. There are many easy ways to determine that. If you're considering a remora for use in a sump, then what you actually want is the urchin. Same thing, but designed for sump use.
My last tank used an urchin with a mag-3, but it was only 60g, and I only used it because I got it dirt cheap used :P
For example, MAP on a remora/urchin with an MJ1200 is 164, 20-75g of water... more realistically 50 max (IMO) for $150 you can get a Reef Octopus Needlewheel 110 that will handle a max of 100g (75-90g IMO)