Researching Greenhouses

I've been battling with things in the garden for several years.  The more garden blogs and pics I see the more I want a greenhouse.  This seems to be the way to go to get plants grown and healthy enough to put outside.  This is one of my downfalls of gardening with seed.  I invariably put things out too early.  Usually I'm running out of room in the house or the weather pretends it's going to behave.  

Greenhouse by Exaco.    There's no prices on the website.

Greenhouse by Duramax at Lowe's.  This one is under $1000 and is the largest so far for our budget.  70 square feet.  I'd like to be able to attach shelves along the sides.  I don't know if this is possible.  If not I'd have to buy metal shelving units to maximize space.

 

A one piece unit from Solar Gem.  No prices on the website.  I've emailed them.  I'm not sure how much I like the look of this.  Obviously I can't attach anything to the sides and I would have to have shelving units.

The biggest consideration for choosing a greenhouse here is wind.  It would be pure foolishness to consider anything with soft walls such as polyethylene.  I might as well throw my money out the window. 

I have awhile to consider what I will get.  It's pretty much too warm here now to have anything growing in a greenhouse.  It would only be used for storage or protecting plants at night from critters.

My only other choice is to carve out space somewhere in my house for 3 months out of the year and just be more patient with growing inside.