Sounds like you are planning to go for a high-ish tech planted tank assuming you're planning on a compressed CO2 unit and not the DIY sugar + yeast setup. CO2Art from UK has premuim CO2 regulators and good quality needle valves for precise bubble rate adjustment but the cheaper units do fine as well but may have less sensitive needle valves.
Substrate wise for planted tanks, if you are planning to go Dutch style, you'll probably be fine with most substrate since most stem plants are water column feeder so a good quality liquid fert would suffice. For other styles e.g. jungle, iwagumi, etc. and for heavy root feeders e.g. cryptocoryne, echinodorus, etc., the current go-to substrate would probably be ADA Amazonia (Normal or Fine), Fine version would be easier for carpeting plants with small roots but you'll need it to be established before introducing larger type corydoras; any of the 3 species of dwarf corydoras would be fine. ADA Amazonia does require a lengthy cycling period due to ammonia leeching so it would be best to start the cycling process early before introducing live stock.
Fully adjustable full spectrum LED lights would be ideal. Check out MakeMyLED, a SA company which specialises in lights for planted tanks.
Good luck and enjoy the hobby!