This is a tough question.. I mean you can get some rimless 75's that are not drilled and then some that are center drilled, still looking at a price.. The hardest part of this hobby is figuring stuff out. This makes me question if you have had a tank before. It makes me wonder why you chose 75. I used to think that having a big tank was a benefit.. more water, less commitment to being there cause of having more water. After doing this for so long I personally feel that people should start smaller. Yeah it is a tough road, but you learn and to be honest if you can do a smaller tank and keep the parameters then chances are when you upgrade to a larger tank it will be that much easier. I feel like working with a smaller tank might be tough but you learn so much and IF you do it well then transferring your current tank to a larger one is that much easier. Also, with a smaller tank you might not use as much funding and if you fail or Real Life (RL) gets in the way, the losses aren't as bad.
A friend of mine once started with a 20gallon long and I thought for sure that it was going to be **** storm. Not drilled, needed overflow and all that, but in the end the tank was amazing.. Its tough to tell you what to do, but I certainly would not get a custom made one until you have a few years under your belt. That is for sure.. Read, learn, see, ask, understand peoples mistakes and then come to a decision. There are couple 75 gallon rimless, but to be honest.. I prefer a tank that has a rim, around 1.5 inches. In the past I have had rimless and ended up putting black electrical tape around the tank. Reason: unless your floor is 100% level seeing that uneven water level every day can really drive you to drink. Maybe it's just me.. Having that rim hides that. Just a thought..
