You will get mixed reviews on this subject. Specially from fan boys who never used a system they just put down. All critique aside, you have to consider how much money you are willing to put out, and how hardcore you want to go? Many users never even think of buying really expensive Pro grade glass.
A friend of mine asked me for help this week. She was humble on her demands, but I gave her a ton of options.
At $800 you are a little limited. My recommendation would be the E620 two lens kit. You get an EFL of 18-300mm. Those kit lenses are tack sharp f/5.6 and beyond, but IMO wide open is very much ahead of the competition kits. The Sigma 105mm macro is a superb lens for the price. A used copy can be had for $325~$400. Brand new sits at $480. *Note* The 4/3 system has a 2x crop factor. So the 105mm turns into a 210mm. A much nicer reach when compared to APS-C reach of 150~160mm with like sized lenses.
Another strong option is the Kx with two lens at around $600. You still get EFL of 18-300mm. The Olympus kit glass is sharper than the Pentax, but Pentax kit glass is much better than Canon's and Nikon's. I can't comment on Sony's kit glass, but my peers don't think highly of them. Pentax does offer more options with macro glass. Either one you pick will be pretty sharp including Pentax's Macro.
You can't go wrong if you pick the big boys Canon and Nikon, but expect to pump more money. Good Luck
Edit: I forgot to mention Adorama has the E620 kit Refurbished from Olympus for $550. A heck of a steal for it.