I would not recommend a skin unit for the first time. I did that and couldnt get the front to the indetectability levels I wanted. Also, the feeling sensation and sound on the scalp is different, more "plastic" than lace. The poly sides and back are no problem though, and are easy to work with.

Lace has a more natural feel, and at the beginning I think it's psychologically easier to wear, as for your first time you want to feel as natural as possible.

I agree with Paul's advise: french with skin strip on sides and back, or full french lace (swiss is more fragile for a novice). I now use all french lace and I do not see any disadvantage to it.

You will have to learn a lot of things at first, you will be stressed.So i recommend to start wearing at the beginning of some holidays if you can, so when you start working you will be more comfortable with all the process.

My first 2 months were difficult, now I can say Im happy and dont worry about hair. And by the way, if you want that much density (dont overdo it!), and comb forward, you have it easier.

PD:I suppose you know that stock units are cheaper