We have both the Common Pleco and the Bristlenose Pleco in our profiles. They are different fish.
All "bristlenose" are similar in size and requirements as noted therein, the main difference being the "normal" BN and any wild-caught rarer species. All are in the Ancistrus genus so they have similarities.
We also have a couple of "pleco" in the Hypancistrus genus, the much sought-after Zebra Pleco and a relative. Some of these are fine in smaller tanks, though I personally wold not put one in anything under a 20g long.
The Common Pleco is a large fish, and should be avoided except for very large tanks.
Hillstream Loach would be nice even in a 10g, but recognize two things: cooler temperatures (low 70's max) and fast water flow. This is an ideal fish for a temperate tank (not heated) with a HOB filter for lots of current. Obviously other fish in the tank must have similar requirements, and that is not easy. White Cloud Mountain Minnow are about it (but also not in a 10g) unless you are fortunate enough to have some good importing stores/dealers. The most common species of HL is in our profiles, click the shaded name.
Substrate fish are not easy to find for a 10g. Corys obviously work, 3-5 of the average species or 9-12 of one of the dwarf species. Even the dwarf species of loach are too large for a 10g, but perhaps a small group of Kuhli loach would work. Shrimp also work, depending upon upper fish (may eat them
). A whiptail catfish would manage.