If you're frustrated by having the cash and just not pushing through and finding a shop tp finish it the way you want it, then parting it out will frustrate you even further. One doesn't build what you have and stop mid-stream if one wants to retain any money. If you're not willing to find a professional shop with a great reputation even elsewhere in the country, then just sell it, and be prepared to lose your cash value. Parts are not worth much, and you will get .50/dollar for a brand new engine unless you are very close friends with the buyer. Selling parts sucks, and that comes from someone with 30 years experience doing it...lol.
If it were me, I'd just find a shop, sign a contract with them, and send them the car. You have a chance to get something back with the car done. You will never get what you will need to put into it, but if it's truly a case of just giving up and getting out, that won't matter. Again - I did that some years ago. I scrapped over 3 tons of iron, gave away 10-15 transmissions, junked 2 cars, etc etc. If you want out, get out. If you want to finish it, finish it. Standing still comes from not being decisive for reasons only the individual knows. Lifes too short - get past it.