If i were doing this job for a customer i would install a Fatmans mustang 2 crossmember and buy used "A" arms and front suspension parts and rebuild them to keep the cost down. When i finished my customer would love the ride and handling of his truck.
Seeing you already have a S-10 frame, This would be my 2nd. choice. I would want to use a extended cab or long bed frame. The S-10 frame is made to be shortened. They shorten these frames at the factory with a "fish mouth joint". This frame swap works out real good. But it's a lot more work and a lot more hours. I have done 2 S-10 frame swaps ,if you need some help feel free to ask me. Hope this helps. Regards, HonestFrank frank@tcdi.net