Tekkit SMP by CraftersLand is a Tekkit SMP modpack server with a survival setup built around land claiming, so you can settle in and build without every base turning into a mess. If you like modded SMP with a bit of structure, this one leans into that style pretty clearly.
There's also an economy side to it with server shops, a market, and auctions, plus daily and vote rewards to keep things moving along. Clans and PvP are part of the mix too, so whether you want to team up, trade, or scrap a bit, there's room for that.
The server also has a live map, which makes it easier to keep track of the world and find your way around. If you're looking for a Tekkit server with survival, claims, economy, and a community feel, this is basically the pitch.