Depends on your budget and desires. I would definitely suggest a MT or stretchy wrap for someone who is a walker. Anything that supports the baby with both shoulders will be more comfy for you as it will distribute the weight more evenly.
Personally, I'm a sling girl but I only do short walks and pop in and out often.
I know many mamas (me included) that have several different carriers for different purposes. If you know someone who sews, you can make them much cheaper than buying them at retail.
Here are some great free patterns to all sorts of carriers.
Like MB, I wouldn't trust the quality of anything Wal-Mart sells (I'll stay out of their crappy ethics side of the argument for now
).
Siana and zabsmom both make MTs and you can easily make a no-sew stretchy wrap yourself by using
these instructions.
MM