What position do you think they need to fill with their first pick in the draft? I think you have to take whatever top lineman is available for either the offense or defense that fills a need. I'm thinking C, OG or NT.
I am of the opinion that all early round picks (rounds 1-4) should almost exclusively be used on the best player available. There are some exceptions, particularly with quarterbacks, but Miami doesn't need to use a high draft pick on a QB this year so that's not a concern.
I'm also generally against drafting running backs really high, since apart from the true greats, that position is incredibly fungible.
So QB and RB are really the only two positions I'd ignore in the first round this year.
Your idea to take the best lineman available is a sound one, since Miami needs help on both lines. The problem, however, is that Miami shouldn't reach for one of these positions if the player isn't worth the draft slot. Remember, Miami has Washington's second-round pick this year (around pick 44 I believe), so they won't have to wait too long between picks.
I think Miami should also strongly consider taking a pass rushing linebacker, physical shut-down cornerback, or big-bodied possession receiver with their first pick, if the right value is there.
I've yet to really start studying the draft class, but some guys to possibly keep an eye on for Miami's first pick include CB Vontae Davis, LB James Laurinaitis, LB Brian Cushing, NT B.J. Raji, and C Max Unger.
After free agency gets under way, we'll be able to talk about the draft and Miami's needs with some more clarity.