Re: Transmission
Converting from auto to manual would require all the right donor parts and a ton of time and work to complete. If you were putting together a streetrod or muscle car it might be worth it, but generic every-day transportation isn't worthy of the hassle and expense it would involve.
I'd dump the car now, or repair the auto trans and drive it until the wheels fell off, assuming you have good reason to believe you can drive it for quite a while after the repairs have been made. If you repair it, then sell it, you'd probably do so at a loss.