Was thinking X-Ray tetras or Silver Tips. Hadn't decided yet. Looking online it looks like they'd also be good around 78F, right?
Is there a good list somewhere I can use as a checklist of what I need to get? Like vaccuum pump-thing for cleaning/water changes (any recomendations?). 5 gallon bucket right? Fish net, heater, filter.
I would not recommend Silvertip Tetra here; they are a bit active for the gourami, and they have been known to fin nip slower fish sometimes. The X-Ray presumably are Pristella Tetras, species
Pristella maxillaris; perhaps a bit active for this set-up, but not overly so. However, this brings me to another factor in deciding fish, and that is the level in the water column where a species tends to remain.
Gourami are upper level fish, at or near the surface, above mid tank generally. Loaches obviously are substrate-level. Pristella also tend to be upper level, and they are not especially colourful so they sort of blend in with the gourami. I like the Pristella, I have had it a couple times, so nothing against it. But if you want to add a bit more colour, and in the mid to lower level to balance out, in the tetras something like Rosy Tetra, Roberti (Ornate) Tetra, Red Phantom Tetra would be nice. Here's data:
http://www.seriouslyfish.com/species/hyphessobrycon-rosaceus/
http://www.seriouslyfish.com/species/hyphessobrycon-bentosi/
http://www.seriouslyfish.com/species/hyphessobrycon-sweglesi/
As for equipment, a water changer is needed. A couple buckets (2-3 gallon) used ONLY for aquarium/fish [any soap or chemical substance in a bucket of water can be very difficult if not impossible to remove, so buy clean buckets and use them for nothing but fish things]. Water is heavy, each gallon weighs about 10 pounds, and I find a 2-3 gallon is as large as I ever want to be hauling around. Fish nets, different sizes; I have a very small one (about 2 inches width) which is handy for netting out floating plant leaves or similar, and a 4-inch width and a 6-inch width, or something like those. Filter obviously, and heater. Water conditioner...I use and highly recommend API's Tap Water Conditioner; it may seem expensive by comparison but it is very highly concentrated so you use very little...one drop dechlorinates 1 gallon. A medicinal-type eye dropper is useful to measure out drop by drop. A test kit for pH, ammonia, nitrite and nitrate; the API Master Combo has these four; liquid test kits as opposed to strip tests are more reliable.