One option you may want to look into, especially as a DIY project, it using epoxy paint. Kelley Technical makes the paint that I've always used, and it is a reliable product IF you follow the DETAILED instructions they have on their site:
http://www.kelleytech.com/olympic/
The nice thing for you is that you can use an epoxy patch to fill in bad areas, and then immediately follow with epoxy paint, and you can use the SAME finish on both surfaces. One caution: you cannot immediately coat cement (concrete, sorta) based patches with epoxy.
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