Gaps are good.
See this
Its seldom you get to see lashes on someone, so it gives you an idea how quite a stripy lash can look rather clusters of lovely long lashes fresh out the shower instead of silly!
Lashes that go long in the middle and shorter on the outside have an eye opening effect. Ones with them longer at the outer edge can look funny on a lot of eyes.
A good website is Eye Beauty
From this website I've had the Naiomi, the Giselle, Ardel Gypsy lashes in the brown, and the tangly black ones (demi wispy tangly I think they were). I found the wispy ones a bit too long and a bit too wispy - I think I prefer ones that cluster or stripe, I like that cluster effect that I just can't get with mascara without clogging.
Dammit I'm going to have another wee browse on that website now because Ive just seen something!
If you have time go to a Mac counter and browse their range. They have a fine range.
Boots have a good selection too.
For a starter, I would suggest something that gives a bit of volume, a bit of length, isn't too black or too dense, and a little clustery but not too much, and doesn't sweep up at the ends but in the middle (i.e longer lashes in the middle) - then you wont be overly dissapointed and will get to see how certain attributes of the lash look on, and the things you like about it you can step up a notch with a different style and if there's something you dont like you can avoid. That would be a good all rounder to start with.
Good luck!