Shekdown,
First, I would like to say that you definately should learn to play chords, even if tab is easier at this moment. Being able to play and find chords is a necessity as a musician and guitarist; so I wouldn't procrastinate on that ( Even if it's hard to catch on at first ).
Next, I will address your question/issue. Feeling comfortable with moving your fingers around the fretboard, is all an issue of practice. However, I will give you an exercise you can practice so that this skill can increase as fast as possible.
1. Get in your comfortable playing position and place your hands to their correct spot.
2. Make sure you are COMPLETELY relaxed. You do not want any uncomfortable tension in any part of your body while you practice. If you do feel tense, be aware of this and make it an issue to relax those muscles.
3. With your left hand ( or right hand if you are left hand dominant ), place your finger on the correct fret and string according to the tab you are learning to play.
4. When you are ready, make a conscious effort to play it as SLOWLY as possible, while looking at your finger and then premeditating where the next note is. Again, if you feel any tension, stop what you are doing ( keep your hands in position though ) and relax that tension.
5. Do this all the way through a few times and your fingers will have learned the correct way to play this song. Muscle memory will kick in and you can slowly increase speed until it is at the desired tempo.
Remember, there are no quick fixes in music. However, if you practice this way, then you will become a better guitarist, at a much faster rate.
Hope this helped!
P.S. Use the same practicing technique to keep your fingers arched. Make sure the tips of your fingers are only touching the string and ALWAYS stay relaxed.
-Kyle Hicks ( Kole )
-http://www.myspace.com/kolemusic
-Kole (Kyle Hicks)
http://www.KoleMusician.com
http://www.myspace.com/kolemusic
Composer, Guitarist, Instructor.