Help me buy a DVD burner

Basically I am looking for an external DVD burner so that I can free up some space on my Tivo, and and watch my shows in another room (without using my computer). I have been looking at a bunch of burners, but all they are doing is confusing me. I bought a fancy Toshiba burner the other day, but I don’t think I need a fancy burner, and I think I would like something a little less expensive. I don’t really intend to record live TV, because I have Tivo for that.

I see a lot of burners on ebay for under 100.00. The DVD recorder I bought hooks up via RCA cables, but I see that some hook up via USB. Is a USB recorder going to be faster? Is it good for just for burning files from Tivo? Plus there is all this DVD +R and DVD- R stuff which perplexes me. I get the feeling that dual layer is good, because you can fit more stuff on a disk that way. Can anybody enlighten me?

I’m usually pretty good at this technical stuff, but I just can’t wrap my brain around DVD burners/recorders/writers (???). I use a Mac computer (if that matters), I have a series 2 Tivo, and I also use a Digital cable box.