Getting a greenhouse

[kdodds]

Well, got the go ahead on a greenhouse...

Purpose:
1. Overwinter of bonsais.
2. Grow out of bonsai species in season.
3. Will not be used for starting anything else, growing anything else, or housing anything else over winter, just the trees.

Requirements:
1. Somewhere between 6x8 and 8x12.
2. Green or Black frame, no silver.
3. Shelving included, preferably.
4. Auto-vent kit included or available.
5. Sturdy enough to last a decade or more.
6. Included rain gutter system would be a huge plus.
7. Budget of ~$1k with shelves/tables, auto-vent, and rain gutters.
8. Simple kit, not looking for the ultimate in grow zones, just something simple.

I'm looking at the following makes/models so far:
1. Bio-Star 6x8
2. Nature Greenline 6x8
3. EasyGrow 6x8
4. Snap & Grow Green 6x8

So far, leaning toward the Nature Greenline (rain gutters included, but unknown if shelves/auto-vent are included or available). The Bio-Star has the best price, even with add-ons, but doesn't seem to have a rain gutter kit, and looks a little flimsy. The EasyGrow has tons of accessories, but I couldn't find a rain gutter kit, and the starter price is almost the full budget. The Snap & Grow also has plenty of options, but again, not clear if it has a rain gutter option, apparently does not come with shelves, and is also up there in price.

If you have any of these greenhouses (or even another brand/model), I'd love to hear your input.