Having a big farm already on board and aiming for lower fees could really help your mining pool stand out if you can find the right developer to join you.
Yeah, hope OP has managed to build his 1% fee pool by now. There are a lot of open sourced btc mining pools that any interested one could check out on github.com at least there used to be anyways. Miningcore is a well liked high‑functional pool server written in C#. One more rigid pick is NOMP, a Node.js‑based, easy‑to‑deploy solution together with stratum support and a built in web portal. Actually I know there is a public Pool app for UmbrelOS that is plug an play, offering a solo mining pool environment. If anyone wants to make custom templates straight away from node then DATUM is good choice.