The only thing holding you back is your $1,000 budget.
The trans you would need is going to run you $5,000. I know this because I priced one for my build, and that's when I decided to demod.
As far as the turbo itself, I wouldn't use a semi-turbo. I would use an ebay knock off of a name brand turbo. As far as the turbo crossover, with a welder and some pipe it wouldn't be too hard to fab something up. Plan ahead, space will be limited.
After you spend money getting your hotside setup, you'll need a boost controller that keeps you from going over 6 psi, and a tune for boost. Get HPT and do it yourself. That should all get you over your budget but by less than $500.
In all reality, if you can't afford a new engine and trans, you should leave this idea alone.