Re: Foundation help
It really depends on how severe your acne scars are. I have pretty severe scarring and deep hyperpigmentation, and I always look for full coverage. Even then, I usually need a separate concealer to cover blemishes and dark spots.
The uneven complexion might be taken care of by a medium-coverage foundation, but the scarring might not. :\ You could either go with a concealer for the scars or try to build up the coverage of a medium-coverage foundation.
But personally I'd suggest you go with a full-coverage foundation for a couple of reasons:
1. You can always sheer out the foundation with a damp sponge for the places that don't need as much coverage, and sheering out foundation is generally easier than building it up.
2. Most foundations that claim full-coverage aren't really THAT full; they're more of a medium to full coverage, meaning that you can build it up. Following that trend, if you go for a medium-coverage foundation, the coverage might be even more sheer than you're expecting and you could only build it up to a medium coverage.
3. You might not need to buy a separate concealer if your scars aren't that severe, and the full-coverage foundation could just be dabbed on your problem areas to serve as a secondary concealer.
Honestly though, the coverage that a lot of products claim is very subjective. It's like sizing; a small in one brand might not be a small in another brand. You should definitely go to a Sephora and have an associate help you try out some different foundations you might be interested in.
Hope this helped a little. (:
Re: Foundation help
I'd go with "medium" until the redness goes away. For me, full is just way to full and cakey. People want/need to see your skin, and most people are turned off by someone who has too much packed on.
You might want to try Lancome's Dual Finish Foundation because it covers without ever caking or settling into lines. It also really makes the skin look flawless. It's my all-time fav!