mmnoname,
It depends on which broker you use, all are different in their own ways, so do your research well and find one that fits your trading style.
Take a look at O A N D A, there is no limit in size to positions, (as long as you have the margin). You can trade Full, .01, .001 lots or any size you like. However to my knowledge there's no plug in for
Metatrader. So you'd be trading and charting on two different charts. Which isn't all that bad sometimes.
Hope this helps,
Bear