Hi, Mudcatters!

I'm looking for a slide-blues guitar (not country), but not too expansive like national or dobro.
I don't know anything about this kind of guitar but I'd like to learn to play it.
Some friend suggested me an Epiphone Biscuit (Mogany body) or an Epiphone MD 100 (Metal body); what's the best for blues? Wood body or Metal body?
Please, help me!

Thanks!