I'm certainly not an expert in this area, but I did rebuild my 302. I didn't want a radical "lope" to my engine idle, so I kept my cam at a 256 grind. I understand that if you go over 260, you will get a definite "lope" at idle. I used a COMP cam (Part #FS XE256H-10) I also installed hydraulic lifters, forged aluminum pistons and rebuilt heads. I wanted to have my original heads rebuilt, but I was advised that I'd be money anead with aftermarkets. I purchased mine from "Powerheads" (Powerheads.com). So the heads retain an original look. If you are wanting to keep it original, then I would probably sink the bucks into having your heads rebuilt by a competent machine shop. Also, if are going to do the tear down and rebuild yourself, I would recommend the following book, available through most Mustang Supply outlets:
How to Rebuild Small-Block Ford Engines: Tom Monroe, HPBooks. Rebuilding your own engine can be a rewarding experience. If you are not adventurous and mechanically inclined, I would probably just send it out and have it done.
Just some thoughts and my 2 cents. Let me know if I can help.
Steve