Ok I have an 07 schwinn fastback sport that some had changed over to bar ends, a deore rear derailleur, a random front derailleur, and a 6 rear cassette. I want to put brifters back on it. If I changed the cassette back to an 8 speed and made it a single front chainring what all would I need? Don't worry about front derailleur as wouldn't need it. Would the rear work? Just buy a single shift/brake lever (right side) that is an 8 speed compatible? Or what is your guys ideas. I'm just worried about buying stuff and it doesn't work. I want to do it myself so please no lbs as there isn't oNE within an 1.5 hr from me.

What problem is you trying to fix?
If shopping and support is difficult for you, follow the old saying "if it aint broke, don't fix it".
A 6-speed can be both freewheel and freehub.
6-speed freehubs won't take 8-speed cassettes.
Some 6-speed freehubs can be replaced with 8-speed freehubs.
Will take some homework.
There are 8-speed freewheels, but they are held to be prone to axles bending.
Probably easier to find another wheel.
Using only one out of 2/3 chainrings is a so-so thing.
(Externally) bikes are designed to let the chain move with relative ease from one gear to the next. Now you want the chain to stay put. It's common to have to add either chainguides or to use special chainrings to keep the chain in place.