Inquire with Maschino's in Springfield.

As for people who can give advice on plants, contact the Master Gardener's Organization, ask around at the farmer's market (I know some of the vendors do landscaping as a regular business), check the phone book, ask other greenhouses like Steinert's or Carson's for recommendations, etc.

Here is a link that might be useful: Maschino's

Some of the landscape designers in the phone book only work for businesses and won't do designs for home owners. I'm trying to remember the name of the nursery that's next to Steinert's. They will do designs for home owners or at least they used to. I'm not sure they're still there. Their plant selection isn't all that good but they had a photo album full of pictures of work that they'd done at a Lawn and Garden show in Springfield a couple years ago that I thought looked pretty good.
How about checking with real estate agents in your area and see if they could give you some names. Good landscaping helps homes sell, so it seems like they should know if they've been around for awhile especially real estate agents selling upscale homes.

As to the firebox: I've seen some nice metal chimanaeas at home depot. I like these better than the ceramic ones because the fire can be viewed from all sides. I have a simple fire ring in my garden made of rocks. I would think 10 feet is not too close to the house if you remember to only burn when there's not too much wind, you're not in a drought and there's not a whole lot of vegetation including dead leaves nearby.