well here are some good rimless that are already drilled they offer multiple sizes, I know because I have looked into rimless tanks as well.
Current USA's line of Solana offers several sizes up to 67 gallon and some even have the sump, stand included.
Next there is the Finnex line that offers some smaller sizes.
Cadlights which is what I am going to get is very versatile and has many different sizes at an affordable price.
Elos are nice tanks and an option but they are really expensive.
Glasscages makes custom rimless tanks but If you do that I would go with Reef Savvy custom tanks.
*some notes are to check the glass thickness on rimless some powerheads (like vortech) have a max thickness to operate on.
the filtration ballpark would be in the $200-400 range easy esp if you add ATO, reactors and all the stuff. and don't forget a reliable return pump (my favorites are Sicce USA and Eheim)
also yes research until you are sick this will help you get the most value out of your equipment. two import things are an RO/DI and a Refractometer. The refractometer are quite affordable at about $40+ and a basic RO/DI would run in the $100+ range.
also I wouldn't go with sugar fine sand I would go with aragonite in the 2mm size range, my favorite is Tropical Eden Reef Flakes.
my 50g rimless system I have estimated to cost in the $2500 range +
(mostly because of LED lights are over $1000 but worth it)