|My test blog - WordPress free template: CORALINE|
There's a slight difference in uploading the background to a WordPress blog - as with TypePad, the image has to come from your own computer - which makes things difficult for the designers of freebie templates re credit, kudos and copyright issues. So I suggest you do the right thing and add their button to your site, in your sidebar, with a little header such as 'Template from...', which sorts the issue nicely (as far as I am concerned re my own designs, anyway).
If you have the right package(ie: Theme Builder) then you can also add any freebie templates. The maximum default for Theme Builder is 900 pixels wide, so most 3-col Blogger background designs will fit! Hurrah! Again, you need to download the image to your own computer and then upload to your TypePad account.