baby carrier for gardening?

I'm posting here instead of the babywearer.com forum b/c I remember to read
this group and that's about it.
I have made several ring slings, wraps and a Mei Tai. I also have two
structure soft carriers (infantino and one with Pooh on it). I tried all of
these yesterday trying to get my 5month old (15lbs) into a high back carry
so I could garden. I could get her into a regular back carry with the MT
and the structured carriers, but she's down so low she can't see anything.
She screams if she can't see anything. Screaming in my ear is bad. I want
her high enough she can look over my shoulder, but secure enough I can bend
over and weed or dig. I seem to be completely unable to do a back wrap
carry of any kind (rucksack, tibetan, etc) because I just can't get her up
on my back high enough. When I try the "toss" method, both of us freak out
and she's still in a low position anyway. I can't seem to scoot her up
enough.
So, any tips to doing high back carries would be helpful (I've looked at
www.thebabywearer.com and most of their associated links).
Actually, for anyone who does use a baby carrier for things like gardening
or yardwork, what do you use, and in what position? I'm just wondering if I
should work on using the wrap with help from a partner, or focus on the MT.
I may make another MT since the one I made is felt and fleece, so it has no
stiffness. I'm wondering if a cotton light canvas would hold it's shape
better.
Any suggestions appreciated. I've used www.sleepingbaby.net for my patterns.
If I can't find something to make, I am wondering about those hiking framed
backpacks. Expensive, but I could try to find used. It just seems too
bulky to be useful for gardening when I'll be up and down.

Thanks!
Amy