I have a 2ft tank with a eheim 2215 i picked up of a facebook group for $50. I also like Rummynose tetras just as much as cardinals and neon tetras. If your going planted get as as many plants as you can to start off with and ottos over bristlenoses. Also to help with cycling maybe someone close by can spare you a bit of media to get the bacteria up and going.
As for maintenance. I clean the canister every 2-3 months and do 30L water changes every week. If that helps. I am still new to the hobby too.
my stocking is a bit heavy but never any problems
5 harlequin rasbora
1 hillstream loach
2 bn 1m & 1F
5 albino corys
1 pepper cory
Hope this helps. Feel free to drop a pm.